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A212264
Diagonal sums of triangle A096815.
3
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
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
Sequence in context: A157876 A289433 A351973 * A174650 A107293 A329693
KEYWORD
nonn
AUTHOR
Emanuele Munarini, May 12 2012
STATUS
approved