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A027719 Numbers k such that k^2 + 1 is a palindrome. 4
0, 1, 2, 10, 25, 100, 1000, 1020, 1489, 2248, 10000, 10090, 100000, 100910, 102020, 167491, 1000000, 1000200, 1009090, 2744934, 10000000, 10000900, 10090910, 24917195, 100000000, 100909090, 103226660, 271867456, 1000000000, 1000002000, 1009090910, 1577033471 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Giovanni Resta, Table of n, a(n) for n = 1..48

P. De Geest, Palindromic incremented squares of the form n^2+1

MATHEMATICA

palQ[n_] := Block[{d = IntegerDigits[n]}, d == Reverse[d]]; Select[Range[0, 10^5], palQ[#^2 + 1] &] (* Giovanni Resta, Aug 29 2018 *)

CROSSREFS

Cf. A002522, A027720, A002778, A070253.

Sequence in context: A305600 A058373 A167386 * A254709 A069894 A045605

Adjacent sequences:  A027716 A027717 A027718 * A027720 A027721 A027722

KEYWORD

nonn,base

AUTHOR

Patrick De Geest

EXTENSIONS

More terms from Giovanni Resta, Aug 28 2018

STATUS

approved

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Last modified January 18 07:55 EST 2022. Contains 350454 sequences. (Running on oeis4.)