S( n, m) = S(n-1,m-1) + (n-1) * S(n-1, m) S( n, 1) = (n-1)! S( n, n) = 1 S( n, n-1) = [n*(n-1)]/2 X = S(10, 7) S( 2, 1) = 1! = 1 <-- S( 3, 1) = 2 <--- S( 4, 1) = 6 <--- S( 3, 2) = 3 <--- S( 4, 2) = S( 3, 1) + 3 * S( 3, 2) S( 5, 2) = S( 4, 1) + 4 * S( 4, 2) S( 4, 3) = 6 <--- S( 5, 3) = S( 4, 2) + 4 * S( 4, 3) S( 6, 3) = S( 5, 2) + 5 * S( 5, 3) S( 5, 4) = 10 <--- S( 6, 4) = S( 5, 3) + 5 * S( 5, 4) S( 7, 4) = S( 6, 3) + 6 * S( 6, 3) S( 6, 5) = 15 <--- S( 7, 5) = S( 6, 4) + 6 * S( 6, 5) S( 8, 5) = S( 7, 4) + 7 * S( 7, 5) S( 7, 6) = 21 <--- S( 8, 6) = S( 7, 5) + 7 * S( 7, 6) S( 9, 6) = S( 8, 5) + 8 * S( 8, 6) S( 8, 7) = 28 <--- S( 9, 7) = S( 8, 6) + 8 * S( 8, 7) S(10, 7) = S( 9, 6) + 9 * S( 9, 7) ++++++++++++++++++++++++++++++++++++++++++ S( n, m) = S(n-1,m-1) + (n-1) * S(n-1, m) S( n, 1) = (n-1)! S( n, n) = 1 S( n, n-1) = [n*(n-1)]/2 X = S(20,15) S( 2, 1) = 1! = 1 <-- S( 3, 1) = 2! = 2 <-- S( 4, 1) = 3! = 6 <-- S( 5, 1) = 4! = 24 <-- S( 6, 1) = 5! = 120 <-- S( 3, 2) = ( 3* 2)/2 = 3 <--- S( 4, 2) = S( 3, 1) + 3 * S( 3, 2) S( 5, 2) = S( 4, 1) + 4 * S( 4, 2) S( 6, 2) = S( 5, 1) + 5 * S( 5, 2) S( 7, 2) = S( 6, 1) + 6 * S( 6, 2) S( 4, 3) = ( 4* 3)/2 = 6 <--- S( 5, 3) = S( 4, 2) + 7 * S( 4, 3) S( 6, 3) = S( 5, 2) + 7 * S( 5, 3) S( 7, 3) = S( 6, 2) + 7 * S( 6, 3) S( 8, 3) = S( 7, 2) + 7 * S( 7, 3) S( 5, 4) = ( 5* 4)/2 = 10 <--- S( 6, 4) = S( 5, 3) + 5 * S( 5, 4) S( 7, 4) = S( 6, 3) + 6 * S( 6, 4) S( 8, 4) = S( 7, 3) + 7 * S( 7, 4) S( 9, 4) = S( 8, 3) + 8 * S( 8, 4) S( 6, 5) = ( 6* 5)/2 = 15 <--- S( 7, 5) = S( 6, 4) + 6 * S( 6, 5) S( 8, 5) = S( 7, 4) + 7 * S( 7, 5) S( 9, 5) = S( 8, 4) + 8 * S( 8, 5) S(10, 5) = S( 9, 4) + 9 * S( 9, 5) S( 7, 6) = ( 7* 6)/2 = 21 <--- S( 8, 6) = S( 7, 5) + 7 * S( 7, 6) S( 9, 6) = S( 8, 5) + 8 * S( 8, 6) S(10, 6) = S( 9, 5) + 9 * S( 9, 6) S(11, 6) = S(10, 5) + 10 * S(10, 6) S( 8, 7) = ( 8* 7)/2 = 28 <--- S( 9, 7) = s( 8, 6) + 8 * S( 8, 7) S(10, 7) = S( 9, 6) + 9 * S( 9, 7) S(11, 7) = S(10, 6) + 10 * S(10, 7) S(12, 7) = S(11, 6) + 11 * S(11, 7) S( 9, 8) = ( 9* 8)/2 = 36 <--- S(10, 8) = S( 9, 7) + 9 * S( 9, 8) S(11, 8) = S(10, 7) + 10 * S(10, 8) S(12, 8) = S(11, 7) + 11 * S(11, 8) S(13, 8) = S(12, 7) + 12 * S(12, 8) S(10, 9) = (10* 9)/2 = 45 <--- S(11, 9) = S(10, 8) + 10 * S(10, 9) S(12, 9) = S(11, 8) + 11 * S(11, 9) S(13, 9) = S(12, 8) + 12 * S(12, 9) S(14, 9) = S(13, 8) + 13 * S(13, 9) S(11,10) = (11*10)/2 = 55 <--- S(12,10) = S(11, 9) + 11 * S(11,10) S(13,10) = S(12, 9) + 12 * S(12,10) S(14,10) = S(13, 9) + 13 * S(13,10) S(15,10) = S(14, 9) + 14 * S(14,10) S(12,11) = (12*11)/1 = 66 <--- S(13,11) = S(12,10) + 12 * S(12,11) S(14,11) = S(13,10) + 13 * S(13,11) S(15,11) = S(14,10) + 14 * S(14,11) S(16,11) = S(15,10) + 15 * S(15,11) S(13,12) = (13*12)/2 = 78 <--- S(14,12) = S(13,11) + 13 * S(13,12) S(15,12) = S(14,11) + 14 * S(14,12) S(16,12) = S(15,11) + 15 * S(15,12) S(17,12) = S(16,11) + 16 * S(16,12) S(14,13) = (14*13)/2 = 91 <--- S(15,13) = S(14,11) + 15 * S(14,13) S(16,13) = S(15,12) + 15 * S(15,13) S(17,13) = S(16,12) + 16 * S(16,13) S(18,13) = S(17,12) + 17 * S(17,13) S(15,14) = (15*14)/2 = 105 <--- S(16,14) = S(15,13) + 15 * S(15,14) S(17,14) = S(16,13) + 16 * S(16,14) S(18,14) = S(17,13) + 17 * S(17,14) S(19,14) = S(18,13) + 18 * S(18,14) S(16,15) = (16*15)/2 = 120 <--- S(17,15) = S(16,14) + 16 * S(16,15) S(18,15) = S(17,14) + 17 * S(17,15) S(19,15) = S(18,14) + 18 * S(18,15) S(20,15) = S(19,14) + 19 * S(19,15) S( n, m) = S(n-1,m-1) + (n-1) * S(n-1, m) S( n, 1) = (n-1)! S( n, n) = 1 S( n, n-1) = [n*(n-1)]/2 X = S(10, 7) S( 2, 1) = 1! = 1 <-- S( 3, 1) = 2 <--- S( 4, 1) = 6 <--- S( 3, 2) = 3 <--- S( 4, 2) = S( 3, 1) + 3 * S( 3, 2) S( 5, 2) = S( 4, 1) + 4 * S( 4, 2) S( 4, 3) = 6 <--- S( 5, 3) = S( 4, 2) + 4 * S( 4, 3) S( 6, 3) = S( 5, 2) + 5 * S( 5, 3) S( 5, 4) = 10 <--- S( 6, 4) = S( 5, 3) + 5 * S( 5, 4) S( 7, 4) = S( 6, 3) + 6 * S( 6, 3) S( 6, 5) = 15 <--- S( 7, 5) = S( 6, 4) + 6 * S( 6, 5) S( 8, 5) = S( 7, 4) + 7 * S( 7, 5) S( 7, 6) = 21 <--- S( 8, 6) = S( 7, 5) + 7 * S( 7, 6) S( 9, 6) = S( 8, 5) + 8 * S( 8, 6) S( 8, 7) = 28 <--- S( 9, 7) = S( 8, 6) + 8 * S( 8, 7) S(10, 7) = S( 9, 6) + 9 * S( 9, 7) ++++++++++++++++++++++++++++++++++++++++++ S( n, m) = S(n-1,m-1) + (n-1) * S(n-1, m) S( n, 1) = (n-1)! S( n, n) = 1 S( n, n-1) = [n*(n-1)]/2 X = S(20,15) S( 2, 1) = 1! = 1 <-- S( 3, 1) = 2! = 2 <-- S( 4, 1) = 3! = 6 <-- S( 5, 1) = 4! = 24 <-- S( 6, 1) = 5! = 120 <-- S( 3, 2) = ( 3* 2)/2 = 3 <--- S( 4, 2) = S( 3, 1) + 3 * S( 3, 2) S( 5, 2) = S( 4, 1) + 4 * S( 4, 2) S( 6, 2) = S( 5, 1) + 5 * S( 5, 2) S( 7, 2) = S( 6, 1) + 6 * S( 6, 2) S( 4, 3) = ( 4* 3)/2 = 6 <--- S( 5, 3) = S( 4, 2) + 7 * S( 4, 3) S( 6, 3) = S( 5, 2) + 7 * S( 5, 3) S( 7, 3) = S( 6, 2) + 7 * S( 6, 3) S( 8, 3) = S( 7, 2) + 7 * S( 7, 3) S( 5, 4) = ( 5* 4)/2 = 10 <--- S( 6, 4) = S( 5, 3) + 5 * S( 5, 4) S( 7, 4) = S( 6, 3) + 6 * S( 6, 4) S( 8, 4) = S( 7, 3) + 7 * S( 7, 4) S( 9, 4) = S( 8, 3) + 8 * S( 8, 4) S( 6, 5) = ( 6* 5)/2 = 15 <--- S( 7, 5) = S( 6, 4) + 6 * S( 6, 5) S( 8, 5) = S( 7, 4) + 7 * S( 7, 5) S( 9, 5) = S( 8, 4) + 8 * S( 8, 5) S(10, 5) = S( 9, 4) + 9 * S( 9, 5) S( 7, 6) = ( 7* 6)/2 = 21 <--- S( 8, 6) = S( 7, 5) + 7 * S( 7, 6) S( 9, 6) = S( 8, 5) + 8 * S( 8, 6) S(10, 6) = S( 9, 5) + 9 * S( 9, 6) S(11, 6) = S(10, 5) + 10 * S(10, 6) S( 8, 7) = ( 8* 7)/2 = 28 <--- S( 9, 7) = s( 8, 6) + 8 * S( 8, 7) S(10, 7) = S( 9, 6) + 9 * S( 9, 7) S(11, 7) = S(10, 6) + 10 * S(10, 7) S(12, 7) = S(11, 6) + 11 * S(11, 7) S( 9, 8) = ( 9* 8)/2 = 36 <--- S(10, 8) = S( 9, 7) + 9 * S( 9, 8) S(11, 8) = S(10, 7) + 10 * S(10, 8) S(12, 8) = S(11, 7) + 11 * S(11, 8) S(13, 8) = S(12, 7) + 12 * S(12, 8) S(10, 9) = (10* 9)/2 = 45 <--- S(11, 9) = S(10, 8) + 10 * S(10, 9) S(12, 9) = S(11, 8) + 11 * S(11, 9) S(13, 9) = S(12, 8) + 12 * S(12, 9) S(14, 9) = S(13, 8) + 13 * S(13, 9) S(11,10) = (11*10)/2 = 55 <--- S(12,10) = S(11, 9) + 11 * S(11,10) S(13,10) = S(12, 9) + 12 * S(12,10) S(14,10) = S(13, 9) + 13 * S(13,10) S(15,10) = S(14, 9) + 14 * S(14,10) S(12,11) = (12*11)/1 = 66 <--- S(13,11) = S(12,10) + 12 * S(12,11) S(14,11) = S(13,10) + 13 * S(13,11) S(15,11) = S(14,10) + 14 * S(14,11) S(16,11) = S(15,10) + 15 * S(15,11) S(13,12) = (13*12)/2 = 78 <--- S(14,12) = S(13,11) + 13 * S(13,12) S(15,12) = S(14,11) + 14 * S(14,12) S(16,12) = S(15,11) + 15 * S(15,12) S(17,12) = S(16,11) + 16 * S(16,12) S(14,13) = (14*13)/2 = 91 <--- S(15,13) = S(14,11) + 15 * S(14,13) S(16,13) = S(15,12) + 15 * S(15,13) S(17,13) = S(16,12) + 16 * S(16,13) S(18,13) = S(17,12) + 17 * S(17,13) S(15,14) = (15*14)/2 = 105 <--- S(16,14) = S(15,13) + 15 * S(15,14) S(17,14) = S(16,13) + 16 * S(16,14) S(18,14) = S(17,13) + 17 * S(17,14) S(19,14) = S(18,13) + 18 * S(18,14) S(16,15) = (16*15)/2 = 120 <--- S(17,15) = S(16,14) + 16 * S(16,15) S(18,15) = S(17,14) + 17 * S(17,15) S(19,15) = S(18,14) + 18 * S(18,15) S( n, m) = S(n-1,m-1) + (n-1) * S(n-1, m) S( n, 1) = (n-1)! S( n, n) = 1 S( n, n-1) = [n*(n-1)]/2 X = S(10, 7) S( 2, 1) = 1! = 1 <-- S( 3, 1) = 2 <--- S( 4, 1) = 6 <--- S( 3, 2) = 3 <--- S( 4, 2) = S( 3, 1) + 3 * S( 3, 2) S( 5, 2) = S( 4, 1) + 4 * S( 4, 2) S( 4, 3) = 6 <--- S( 5, 3) = S( 4, 2) + 4 * S( 4, 3) S( 6, 3) = S( 5, 2) + 5 * S( 5, 3) S( 5, 4) = 10 <--- S( 6, 4) = S( 5, 3) + 5 * S( 5, 4) S( 7, 4) = S( 6, 3) + 6 * S( 6, 3) S( 6, 5) = 15 <--- S( 7, 5) = S( 6, 4) + 6 * S( 6, 5) S( 8, 5) = S( 7, 4) + 7 * S( 7, 5) S( 7, 6) = 21 <--- S( 8, 6) = S( 7, 5) + 7 * S( 7, 6) S( 9, 6) = S( 8, 5) + 8 * S( 8, 6) S( 8, 7) = 28 <--- S( 9, 7) = S( 8, 6) + 8 * S( 8, 7) S(10, 7) = S( 9, 6) + 9 * S( 9, 7) ++++++++++++++++++++++++++++++++++++++++++ S( n, m) = S(n-1,m-1) + (n-1) * S(n-1, m) S( n, 1) = (n-1)! S( n, n) = 1 S( n, n-1) = [n*(n-1)]/2 X = S(20,15) S( 2, 1) = 1! = 1 <-- S( 3, 1) = 2! = 2 <-- S( 4, 1) = 3! = 6 <-- S( 5, 1) = 4! = 24 <-- S( 6, 1) = 5! = 120 <-- S( 3, 2) = ( 3* 2)/2 = 3 <--- S( 4, 2) = S( 3, 1) + 3 * S( 3, 2) S( 5, 2) = S( 4, 1) + 4 * S( 4, 2) S( 6, 2) = S( 5, 1) + 5 * S( 5, 2) S( 7, 2) = S( 6, 1) + 6 * S( 6, 2) S( 4, 3) = ( 4* 3)/2 = 6 <--- S( 5, 3) = S( 4, 2) + 7 * S( 4, 3) S( 6, 3) = S( 5, 2) + 7 * S( 5, 3) S( 7, 3) = S( 6, 2) + 7 * S( 6, 3) S( 8, 3) = S( 7, 2) + 7 * S( 7, 3) S( 5, 4) = ( 5* 4)/2 = 10 <--- S( 6, 4) = S( 5, 3) + 5 * S( 5, 4) S( 7, 4) = S( 6, 3) + 6 * S( 6, 4) S( 8, 4) = S( 7, 3) + 7 * S( 7, 4) S( 9, 4) = S( 8, 3) + 8 * S( 8, 4) S( 6, 5) = ( 6* 5)/2 = 15 <--- S( 7, 5) = S( 6, 4) + 6 * S( 6, 5) S( 8, 5) = S( 7, 4) + 7 * S( 7, 5) S( 9, 5) = S( 8, 4) + 8 * S( 8, 5) S(10, 5) = S( 9, 4) + 9 * S( 9, 5) S( 7, 6) = ( 7* 6)/2 = 21 <--- S( 8, 6) = S( 7, 5) + 7 * S( 7, 6) S( 9, 6) = S( 8, 5) + 8 * S( 8, 6) S(10, 6) = S( 9, 5) + 9 * S( 9, 6) S(11, 6) = S(10, 5) + 10 * S(10, 6) S( 8, 7) = ( 8* 7)/2 = 28 <--- S( 9, 7) = s( 8, 6) + 8 * S( 8, 7) S(10, 7) = S( 9, 6) + 9 * S( 9, 7) S(11, 7) = S(10, 6) + 10 * S(10, 7) S(12, 7) = S(11, 6) + 11 * S(11, 7) S( 9, 8) = ( 9* 8)/2 = 36 <--- S(10, 8) = S( 9, 7) + 9 * S( 9, 8) S(11, 8) = S(10, 7) + 10 * S(10, 8) S(12, 8) = S(11, 7) + 11 * S(11, 8) S(13, 8) = S(12, 7) + 12 * S(12, 8) S(10, 9) = (10* 9)/2 = 45 <--- S(11, 9) = S(10, 8) + 10 * S(10, 9) S(12, 9) = S(11, 8) + 11 * S(11, 9) S(13, 9) = S(12, 8) + 12 * S(12, 9) S(14, 9) = S(13, 8) + 13 * S(13, 9) S(11,10) = (11*10)/2 = 55 <--- S(12,10) = S(11, 9) + 11 * S(11,10) S(13,10) = S(12, 9) + 12 * S(12,10) S(14,10) = S(13, 9) + 13 * S(13,10) S(15,10) = S(14, 9) + 14 * S(14,10) S(12,11) = (12*11)/1 = 66 <--- S(13,11) = S(12,10) + 12 * S(12,11) S(14,11) = S(13,10) + 13 * S(13,11) S(15,11) = S(14,10) + 14 * S(14,11) S(16,11) = S(15,10) + 15 * S(15,11) S(13,12) = (13*12)/2 = 78 <--- S(14,12) = S(13,11) + 13 * S(13,12) S(15,12) = S(14,11) + 14 * S(14,12) S(16,12) = S(15,11) + 15 * S(15,12) S(17,12) = S(16,11) + 16 * S(16,12) S(14,13) = (14*13)/2 = 91 <--- S(15,13) = S(14,11) + 15 * S(14,13) S(16,13) = S(15,12) + 15 * S(15,13) S(17,13) = S(16,12) + 16 * S(16,13) S(18,13) = S(17,12) + 17 * S(17,13) S(15,14) = (15*14)/2 = 105 <--- S(16,14) = S(15,13) + 15 * S(15,14) S(17,14) = S(16,13) + 16 * S(16,14) S(18,14) = S(17,13) + 17 * S(17,14) S(19,14) = S(18,13) + 18 * S(18,14) S(16,15) = (16*15)/2 = 120 <--- S(17,15) = S(16,14) + 16 * S(16,15) S(18,15) = S(17,14) + 17 * S(17,15) S(19,15) = S(18,14) + 18 * S(18,15) S(20,15) = S(19,14) + 19 * S(19,15) S(20,15) = S(19,14) + 19 * S(19,15)