a(k,m) tabl head (triangle) for A112493 (used for e.g.f.s of Stirling2 diagonals) k\m 0 1 2 3 4 5 6 7 8 9 ... 0 1 0 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0 0 0 0 0 2 1 4 3 0 0 0 0 0 0 0 3 1 11 25 15 0 0 0 0 0 0 4 1 26 130 210 105 0 0 0 0 0 5 1 57 546 1750 2205 945 0 0 0 0 6 1 120 2037 11368 26775 27720 10395 0 0 0 7 1 247 7071 63805 247555 460845 405405 135135 0 0 8 1 502 23436 325930 1939630 5735730 8828820 6756750 2027025 0 9 1 1013 75328 1561516 13609310 59629570 142101960 186486300 126351225 34459425 . . . Row sums give A006351(k+1), k>=0. [1, 2, 8, 52, 472, 5504, 78416, 1320064, 25637824, 564275648, ...] #############################################################################################################