A062712 Numbers that are n-gons for three or more n's, where n=3,4,5,...,16.

1, 15, 36, 45, 325, 561, 1225, 1540, 3025, 4186, 11781, 40755, 41041, 58311, 121771, 221445, 1334161, 1413721, 1777555, 3000025, 5785101, 27169506, 36855405, 113123361, 321197185, 1167483681, 1533776805, 1631432881

Offset

1,2

References

Albert H. Beiler, Recreations in the Theory of Numbers: The Queen of Mathematics Entertains 185-99 (2d ed. 1966)

Links

Donovan Johnson, Table of n, a(n) for n = 1..58

Eric Weisstein's World of Mathematics, Polygonal Number

Example

45 is a triangular, hexagonal and hexadecagonal number

Mathematica

Select[Tally[Flatten[Table[PolygonalNumber[b, Range[10^6]], {b, 3, 16}]]], #[[2]]>2&][[;; , 1]]//Union (* Harvey P. Dale, Aug 26 2023 *)

Crossrefs

Sequence in context: A219096 A365905 A134509 * A224719 A033709 A067707

Adjacent sequences: A062709 A062710 A062711 * A062713 A062714 A062715

Keyword

nonn

Author

Harvey P. Dale, Jul 14 2001

Extensions

More terms from Eric W. Weisstein, Nov 30, 2003.

Status

approved