A320854 Number of 8-element subsets of [n] whose sum is a triangular number.

1, 1, 5, 17, 48, 122, 276, 573, 1112, 2042, 3578, 6024, 9803, 15476, 23793, 35728, 52522, 75761, 107416, 149923, 206288, 280145, 375868, 498713, 654914, 851807, 1098032, 1403673, 1780402, 2241738, 2803237, 3482687, 4300406, 5279489, 6446078, 7829696, 9463558

Offset

8,3

Links

Alois P. Heinz, Table of n, a(n) for n = 8..1000

Crossrefs

Column k=8 of A284249.

Cf. A000217.

Sequence in context: A011853 A215053 A213767 * A136303 A268783 A273384

Adjacent sequences: A320851 A320852 A320853 * A320855 A320856 A320857

Keyword

nonn

Author

Alois P. Heinz, Oct 22 2018

Status

approved