A054910 Palindromic heptagonal numbers.

0, 1, 7, 55, 616, 3553, 4774, 60606, 848848, 4615164, 5400045, 6050506, 7165445617, 62786368726, 65331413356, 73665056637, 91120102119, 345546645543, 365139931563, 947927729749, 3646334336463, 7111015101117, 717685292586717, 19480809790808491

Offset

1,3

Comments

Intersection of A002113 (palindromic) and A000566 (heptagonal).

Links

Robert Price, Table of n, a(n) for n = 1..29

P. De Geest, Palindromic Heptagonals

Mathematica

Select[PolygonalNumber[7, Range[0, 10^6]], PalindromeQ] (* Robert Price, Apr 28 2019 *)

Crossrefs

Cf. A054971, A000566.

Sequence in context: A326885 A159313 A318580 * A028562 A209668 A340028

Adjacent sequences: A054907 A054908 A054909 * A054911 A054912 A054913

Keyword

nonn,base

Author

Jeff Heleen, May 26 2000

Extensions

Added a(1)=0 by Robert Price, Apr 28 2019

Status

approved