cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A061869 Squares whose sum of digits as well as product of digits is a square (allowing zero).

Original entry on oeis.org

0, 1, 4, 9, 100, 144, 400, 441, 900, 2025, 2304, 2601, 3600, 8100, 9025, 10000, 10201, 10404, 10609, 10816, 11025, 12100, 14400, 14884, 16900, 19600, 21904, 22500, 30625, 30976, 32400, 40000, 40401, 40804, 41209, 44100, 44944, 48400, 48841
Offset: 1

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Author

Larry Reeves (larryr(AT)acm.org), May 11 2001

Keywords

Crossrefs

A061267 does not allow zero products.
Subsequence of A061867.

Programs

  • Maple
    filter:= proc(t) local L;
      L:= convert(t,base,10);
      issqr(convert(L,`+`)) and issqr(convert(L,`*`))
    end proc:
    select(filter, [seq(i^2,i=0..300)]); # Robert Israel, Feb 15 2023
  • Mathematica
    spdQ[n_]:=Module[{idn=IntegerDigits[n]},IntegerQ[Sqrt[Total[idn]]] && IntegerQ[ Sqrt[Times@@idn]]]; Select[Range[300]^2,spdQ] (* Harvey P. Dale, Jan 24 2013 *)