login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A071135 Squares which repeat with at least two full periods when written in base 9. 9

%I

%S 557904400,1255284900,2231617600,508239242281,110723679691024,

%T 267200559990920521,4624943568803015273104,89426738951269414045129,

%U 106343953870710063227329,141828621071731373745001,153228095100765507880225,155946118585671902125225

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

%H Giovanni Resta, <a href="/A071135/b071135.txt">Table of n, a(n) for n = 1..15</a> (terms < 9^25)

%e 23620^2 = 557904400 = 13857|13857 in base 9.

%e 712909^2 = 508239242281 = 171676|171676|1 in base 9.

%t 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 *)

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

%K base,nonn

%O 1,1

%A _Erich Friedman_, May 28 2002

%E a(5)-a(12) from _Giovanni Resta_, Aug 01 2018

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 15 12:44 EDT 2019. Contains 327078 sequences. (Running on oeis4.)