Voozh

A212264

Diagonal sums of triangle A096815.

1, 1, 2, 2, 3, 4, 6, 9, 12, 18, 26, 37, 52, 77, 110, 156, 226, 324, 464, 668, 960, 1370, 1977, 2834, 4060, 5832, 8371, 11993, 17219, 24695, 35408, 50837, 72880, 104619, 150065, 215343, 308868, 443380, 635753, 912581, 1308771, 1878238, 2693939, 3866059, 5544795

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

LINKS

Table of n, a(n) for n=0..44.

MATHEMATICA

T[n_, k_] := T[n, k] = If[n < k || k < 0, 0, If[k = 1 || k == n, 1, Sum[T[n-k, j]T[k, k-j], {j, 0, k}]]]

Table[Sum[T[n-k, k], {k, 0, n}], {n, 0, 50}]

PROG

(Maxima) T(n, k):= if ( n<k or k<0 ) then 0 else

if ( k<=1 or k=n ) then 1 else sum(T(n-k, j)*T(k, k-j), j, 0, k);

makelist(sum(T(n-k, k), k, 0, n/2), n, 0, 32);