A029988 Numbers k such that k^2 is palindromic in base 5.

0, 1, 2, 6, 26, 31, 66, 126, 156, 626, 651, 756, 804, 3126, 3276, 3756, 9054, 15626, 15751, 16276, 18434, 18756, 32578, 34162, 46704, 78126, 78876, 81276, 93756, 390626, 391251, 393876, 406276, 468756, 487981, 1166454, 1953126, 1956876

Offset

1,3

Links

Table of n, a(n) for n=1..38.

P. De Geest, Palindromic Squares

G. J. Simmons, On palindromic squares of non-palindromic numbers, J. Rec. Math., 5 (No. 1, 1972), 11-19. [Annotated scanned copy]

Mathematica

pal5Q[n_]:=Module[{idn5=IntegerDigits[n^2, 5]}, idn5==Reverse[idn5]]; Select[ Range[ 0, 2*10^6], pal5Q] (* Harvey P. Dale, Feb 02 2023 *)

Crossrefs

Cf. A002778, A003166, A007091, A263611, A263612, A029989.

Sequence in context: A009466 A348067 A032479 * A050573 A337573 A331963

Adjacent sequences: A029985 A029986 A029987 * A029989 A029990 A029991

Keyword

nonn,base

Author

Patrick De Geest

Status

approved