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

Author

Jud McCranie, Mar 01 2005

Keywords

• nonn

Links

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

Crossrefs

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

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

Programs

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 *)

Extensions

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