A029993 Squares which are palindromes in base 7.

0, 1, 4, 16, 64, 100, 121, 400, 1024, 1600, 2500, 3249, 4096, 6400, 25600, 40000, 118336, 160000, 250000, 302500, 310249, 532900, 1000000, 1893376, 2050624, 3579664, 5769604, 6007401, 6250000, 7573504, 7845601, 11833600

Offset: 1

Author

Patrick De Geest

Keywords

• nonn
• base

Links

• Seiichi Manyama, Table of n, a(n) for n = 1..100
• Patrick De Geest, Palindromic Squares in bases 2 to 17

Crossrefs

Squares which are palindromes in base b: A029983 (b=2), A029985 (b=3), A029987 (b=4), A029989 (b=5), A029991 (b=6), this sequence (b=7), A029806 (b=8), A029995 (b=9), A002779 (b=10), A029997 (b=11), A029738 (b=12), A029999 (b=13), A030074 (b=14), A030075 (b=15), A029734 (b=16).

Cf. A029992.

Programs

Mathematica

pal7Q[n_]:=Module[{idn7=IntegerDigits[n,7]},idn7==Reverse[idn7]]; Select[Range[0,3500]^2,pal7Q] (* Harvey P. Dale, Dec 15 2011 *)

Formula

a(n) = A029992(n)^2. - Seiichi Manyama, Oct 16 2021