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.

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A071135 Squares which repeat with at least two full periods when written in base 9.

Original entry on oeis.org

557904400, 1255284900, 2231617600, 508239242281, 110723679691024, 267200559990920521, 4624943568803015273104, 89426738951269414045129, 106343953870710063227329, 141828621071731373745001, 153228095100765507880225, 155946118585671902125225
Offset: 1

Views

Author

Erich Friedman, May 28 2002

Keywords

Examples

			23620^2 = 557904400 = 13857|13857 in base 9.
712909^2 = 508239242281 = 171676|171676|1 in base 9.
		

Crossrefs

Cf. A071128 (base 2) - A071134 (base 8), A069919 (base 10).

Programs

  • Mathematica
    psq[b_, nd_] := Block[{sq={}, r, x}, Do[r = Mod[nd, p]; Do[x = (b^( Floor[nd/p] p) - 1)/(b^p - 1) t  b^r + Floor[t/b^(p - r)]; If[ IntegerQ@ Sqrt@ x, AppendTo[ sq, x]], {t, b^(p - 1), b^p - 1}], {p, nd/2}]; sq]; Union @@ (psq[9, #] & /@ Range[10]) (* Giovanni Resta, Aug 01 2018 *)

Extensions

a(5)-a(12) from Giovanni Resta, Aug 01 2018
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