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A057106 Numbers k such that k(3k-2) is an octagonal palindrome. 4
0, 1, 2, 52, 6331, 6431, 7341, 7863, 426115, 453486, 1054067, 1054167, 1472746, 2017631, 42687015, 1050553507, 13175129925, 335038979077, 1400295262095, 5847307263801, 51722791547842, 78849864240621, 105802560494387 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

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

P. De Geest, Palindromic Octagonals

MATHEMATICA

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

CROSSREFS

Cf. A057107, A000567.

Sequence in context: A246485 A121293 A246743 * A080973 A230882 A216354

Adjacent sequences:  A057103 A057104 A057105 * A057107 A057108 A057109

KEYWORD

nonn,base

AUTHOR

Patrick De Geest, Aug 15 2000

EXTENSIONS

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Apr 17 2008

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

STATUS

approved

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Last modified November 17 13:12 EST 2019. Contains 329230 sequences. (Running on oeis4.)