A288631 -id:A288631 - cp's OEIS frontend

A332987 Sums of two nonzero pentagonal numbers.

2, 6, 10, 13, 17, 23, 24, 27, 34, 36, 40, 44, 47, 52, 56, 57, 63, 70, 71, 73, 75, 82, 86, 92, 93, 97, 102, 104, 105, 114, 118, 121, 122, 127, 129, 139, 140, 143, 146, 150, 152, 157, 162, 167, 168, 177, 180, 181, 184, 187, 188, 196, 198, 209, 211, 215, 222, 227

Offset: 1

Olivier Gérard, Mar 05 2020

nonn

Peter Kagey, Table of n, a(n) for n = 1..10000

Cf. A000326 (pentagonal numbers).

Analogs are A000404 (square numbers), A051533 (triangular numbers), A286636 (centered square numbers), A287960 (centered triangular numbers), A288631 (square pyramidal numbers).

Module[{nn=15,pn},pn=PolygonalNumber[5,Range[nn]];Select[Union[ Total/@ Tuples[ pn,2]],#<=Last[pn]&]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jun 15 2021 *)

A330031 Sums of two nonzero tetrahedral numbers (A000292).

Original entry on oeis.org

2, 5, 8, 11, 14, 20, 21, 24, 30, 36, 39, 40, 45, 55, 57, 60, 66, 70, 76, 85, 88, 91, 94, 104, 112, 119, 121, 124, 130, 140, 155, 166, 168, 169, 175, 176, 185, 200, 204, 221, 224, 230, 240, 249, 255, 276, 285, 287, 290, 296, 304, 306, 321, 330, 340, 342, 365

Offset: 1

Peter Kagey, Mar 07 2020

nonn

Peter Kagey, Table of n, a(n) for n = 1..10000

Cf. A000292, A102798, A104246.

Analogs for other figurate numbers are A000404 (squares), A003325 (cubes), A051533 (triangular numbers), A286636 (centered square numbers), A287960 (centered triangular numbers), A288631 (square pyramidal numbers), A332987 (pentagonal numbers).

cp's OEIS Frontend

A332987 Sums of two nonzero pentagonal numbers.

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