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.

A122846 Sequence gives k numbers from A122839.

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%I A122846 #15 Dec 11 2019 05:05:17
%S A122846 1,9,4,36,16,9,81,4,64,35,36,49,16,25,144,15,9,16,100,81,49,4,64,35,
%T A122846 36,196,16,15,25,49,25,144,9,60,9,100,64,100,121,15,16,81,16,4,81,9,
%U A122846 25,16,49,4,25,16,121,25,35,256,114,36,35,81,4,49,16,16,36,4,64
%N A122846 Sequence gives k numbers from A122839.
%C A122846 Almost all terms are squares.
%H A122846 Amiram Eldar, <a href="/A122846/b122846.txt">Table of n, a(n) for n = 1..1000</a>
%F A122846 a(n) = f(A122839(n)), where f(m) = A000203(m)*A034448(m)/A047994(m)^2. - _Amiram Eldar_, Dec 11 2019
%t A122846 f[p_, e_] := (p^(e+1)-1)*(p^e+1)/(p-1)/(p^e-1)^2; ratio[1] = 1; ratio[n_] := Times @@ (f @@@ FactorInteger[n]); Select[ratio /@ Range[10^5], IntegerQ] (* _Amiram Eldar_, Dec 11 2019 *)
%Y A122846 Cf. A000203, A034448, A047994, A122839.
%K A122846 nonn
%O A122846 1,2
%A A122846 _Yasutoshi Kohmoto_, Oct 23 2006
%E A122846 More terms from _Amiram Eldar_, Dec 11 2019