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A320849
Number of 3-element subsets of [n] whose sum is a triangular number.
2
1, 1, 3, 5, 8, 12, 16, 22, 29, 37, 46, 57, 69, 82, 97, 114, 131, 150, 171, 194, 219, 245, 273, 302, 334, 368, 404, 441, 480, 522, 567, 613, 660, 710, 762, 818, 876, 936, 997, 1061, 1127, 1196, 1268, 1342, 1419, 1498, 1580, 1664, 1751, 1841, 1934, 2029, 2127
OFFSET
3,3
LINKS
CROSSREFS
Column k=3 of A284249.
Cf. A000217.
Sequence in context: A183139 A094913 A265060 * A255981 A020678 A310034
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Oct 22 2018
STATUS
approved