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

Author

Patrick De Geest

Keywords

• nonn
• base

Links

• Patrick De Geest, Palindromic Squares in bases 2 to 17
• G. J. Simmons, On palindromic squares of non-palindromic numbers, J. Rec. Math., 5 (No. 1, 1972), 11-19. [Annotated scanned copy]

Crossrefs

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

Programs

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 *)