A071129 Squares which repeat with at least two full periods when written in base 3.

4, 121, 841, 6889, 60025, 62001, 68644, 534361, 540225, 1042441, 4791721, 4809249, 20811844, 43072969, 43125489, 43283241, 387499225, 387656721, 388129401, 567725929, 713584369, 1255284900, 2231617600, 3487020601, 3487493025, 3488910489, 31381768201

Offset

1,1

Links

Giovanni Resta, Table of n, a(n) for n = 1..131 (terms < 3^45)

Example

11^2 = 121 = 1|1|1|1|1 in base 3.
249^2 = 62001 = 1001|1001|100 in base 3.

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[3, #] & /@ Range[20]) (* Giovanni Resta, Aug 01 2018 *)

Crossrefs

Cf. A071128 (base 2) - A071135 (base 9), A069919 (base 10).

Sequence in context: A355751 A098839 A227525 * A241366 A358570 A263612

Adjacent sequences: A071126 A071127 A071128 * A071130 A071131 A071132

Keyword

base,nonn

Author

Erich Friedman, May 28 2002

Extensions

a(25)-a(27) from Giovanni Resta, Aug 01 2018

Status

approved