a(n,m) tabl head (triangle) for A112705 n\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 2 1 0 0 0 0 0 0 0 3 1 4 3 1 0 0 0 0 0 0 4 1 9 11 4 1 0 0 0 0 0 5 1 23 51 22 5 1 0 0 0 0 6 1 65 275 157 37 6 1 0 0 0 7 1 197 1619 1291 357 56 7 1 0 0 8 1 626 10067 11497 3941 681 79 8 1 0 9 1 2056 64979 107725 46949 9431 1159 106 9 1 . . . Row sums give A112706: [1,2,4,9,26,103,542,3529,26901,232416,...] ####################################################################################################