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A296991 Numbers n such that n^2 divides tau(n), where tau(n)=A000594(n) is Ramanujan's tau function. 6

%I

%S 1,2,3,4,6,8,9,12,16,18,21,24,27,32,36,40,42,48,54,64,72,81,84,96,108,

%T 120,128,135,144,162,168,189,192,216,243,256,270,280,288,324,336,360,

%U 378,384,432,448,486,512,540,576,640,648,672,729,756,768,828,840,864

%N Numbers n such that n^2 divides tau(n), where tau(n)=A000594(n) is Ramanujan's tau function.

%C 2^n is a term for n >= 0.

%H Seiichi Manyama, <a href="/A296991/b296991.txt">Table of n, a(n) for n = 1..500</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/TauFunction.html">Tau Function</a>

%t fQ[n_] := Mod[RamanujanTau@n, n^2] == 0; Select[Range@875, fQ] (* _Robert G. Wilson v_, Dec 23 2017 *)

%o (PARI) is(n) = Mod(ramanujantau(n), n^2)==0 \\ _Felix Fröhlich_, Dec 24 2017

%Y Cf. A000594, A063938, A296992, A296993.

%K nonn

%O 1,2

%A _Seiichi Manyama_, Dec 22 2017

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Last modified September 16 18:24 EDT 2019. Contains 327116 sequences. (Running on oeis4.)