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A071128 Squares which repeat with at least two full periods when written in base 2. 9
36, 1849, 6241, 29929, 418609, 672400, 1320201, 7458361, 28121809, 119355625, 302794801, 386554921, 1211179204, 1277991001, 1967188609, 5111964004, 7681646025, 30542106169, 73073443041, 79698371481, 91424593225, 120297291921, 292293772164, 318793485924 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Giovanni Resta, Table of n, a(n) for n = 1..106 (terms < 2^72)

EXAMPLE

173^2 = 29929 = 1110100|1110100|1 in base 2.

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[2, #] & /@ Range[32]) (* Giovanni Resta, Aug 01 2018 *)

CROSSREFS

Cf. A071129 (base 3) - A071135 (base 9), A069919 (base 10).

Sequence in context: A054980 A151640 A025754 * A065782 A160482 A135626

Adjacent sequences:  A071125 A071126 A071127 * A071129 A071130 A071131

KEYWORD

base,nonn

AUTHOR

Erich Friedman, May 28 2002

EXTENSIONS

Missing a(13), a(17), and a(21) from Giovanni Resta, Aug 01 2018

STATUS

approved

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Last modified September 20 22:20 EDT 2019. Contains 327252 sequences. (Running on oeis4.)