A057107 Octagonal palindromes.

0, 1, 8, 8008, 120232021, 124060421, 161656161, 185464581, 544721127445, 616947749616, 3333169613333, 3333802083333, 6506939396056, 12212500521221, 5466543663456645, 3310988011108890133, 520752145595541257025, 336753352502205253357633

Offset

1,3

Links

Robert Price, Table of n, a(n) for n = 1..23

P. De Geest, Palindromic Octagonals

Mathematica

Select[PolygonalNumber[8, Range[0, 10^5]], PalindromeQ] (* Robert Price, Apr 29 2019 *)

Crossrefs

Cf. A057106, A000567.

Sequence in context: A090494 A079656 A114773 * A320864 A052152 A189250

Adjacent sequences: A057104 A057105 A057106 * A057108 A057109 A057110

Keyword

nonn,base

Author

Patrick De Geest, Aug 15 2000

Extensions

a(1)=0 added by Robert Price, Apr 29 2019

Status

approved