A102857 Sum of 1, 2 or 3 distinct tetrahedral numbers.

0, 1, 4, 5, 10, 11, 14, 15, 20, 21, 24, 25, 30, 31, 34, 35, 36, 39, 40, 45, 46, 49, 55, 56, 57, 59, 60, 61, 65, 66, 67, 70, 76, 77, 80, 84, 85, 86, 88, 89, 91, 92, 94, 95, 98, 101, 104, 105, 108, 111, 114, 119, 120, 121, 123, 124, 125, 129, 130, 131, 134, 139

Offset

1,3

Links

R. J. Mathar, Table of n, a(n) for n = 1..4545

Mathematica

Module[{nn=10, tetra}, tetra=Table[(n(n+1)(n+2))/6, {n, nn}]; Rest[Union[ Total/@ Subsets[tetra, 3]]]] (* Harvey P. Dale, Nov 17 2017 *)

Crossrefs

Cf. A104246, A102795-A102801, A102803-A102806, A102855, A102857, A102858.

Cf. A102856 (subsequence), A102802 (subsequence 3 dist. posit.).

Sequence in context: A369654 A131855 A102858 * A102856 A393197 A285135

Adjacent sequences: A102854 A102855 A102856 * A102858 A102859 A102860

Keyword

nonn

Author

Jud McCranie, Mar 01 2005

Extensions

a(1)=0 prepended. - R. J. Mathar, Jun 05 2025

Status

approved