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

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);

Crossrefs

Cf. A096815, A096816.

Sequence in context: A157876 A289433 A351973 * A174650 A107293 A329693

Adjacent sequences: A212261 A212262 A212263 * A212265 A212266 A212267

Keyword

nonn

Author

Emanuele Munarini, May 12 2012

Status

approved