A102856 Sum of 1 or 2 distinct tetrahedral numbers.
0, 1, 4, 5, 10, 11, 14, 20, 21, 24, 30, 35, 36, 39, 45, 55, 56, 57, 60, 66, 76, 84, 85, 88, 91, 94, 104, 119, 120, 121, 124, 130, 140, 155, 165, 166, 169, 175, 176, 185, 200, 204, 220, 221, 224, 230, 240, 249, 255, 276, 285, 286, 287, 290, 296, 304, 306
Offset: 1
Keywords
Links
- Robert Israel, Table of n, a(n) for n = 1..10000
Crossrefs
Programs
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Maple
N:= 1000: # for terms <= N R:= 0: for i from 1 do ti:= i*(i+1)*(i+2)/6; if ti > N then break fi; for j from 0 to i-1 do v:= ti + j*(j+1)*(j+2)/6; if v > N then break fi; R:= R, v; od; od: sort(convert({R},list)); # Robert Israel, Jan 16 2024 -
Mathematica
Module[{nn=12, tetra}, tetra=Table[(n(n+1)(n+2))/6, {n, nn}]; Union[ Total/@ Subsets[tetra, 2]]] (* James C. McMahon, Jan 12 2024 *)
Extensions
a(1) = 0 prepended by James C. McMahon, Jan 15 2024
Comments