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.

A307607 a(n) = 1 + Sum_{d|n, d > 1} d^2*a(n/d).

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%I A307607 #11 Apr 20 2019 03:02:05
%S A307607 1,5,10,37,26,122,50,293,172,330,122,1306,170,642,710,2341,290,2876,
%T A307607 362,3562,1382,1578,530,13082,1276,2202,3088,6946,842,12822,962,18725,
%U A307607 3398,3762,3750,37756,1370,4698,4742,35818,1682,25014,1850,17098,17072,6882
%N A307607 a(n) = 1 + Sum_{d|n, d > 1} d^2*a(n/d).
%H A307607 Seiichi Manyama, <a href="/A307607/b307607.txt">Table of n, a(n) for n = 1..10000</a>
%F A307607 L.g.f.: -log(Product_{k>=1} (1 - x^k)^(k*A074206(k))) = Sum_{n>=1} a(n)*x^n/n.
%t A307607 a[n_] := a[n] = 1 + DivisorSum[n, #^2 a[n/#] &, # > 1 &]; Table[a[n], {n, 1, 46}]
%o A307607 (PARI) a(n) = 1 + sumdiv(n, d, if (d>1, d^2*a(n/d))); \\ _Michel Marcus_, Apr 20 2019
%Y A307607 Cf. A074206, A197953, A307604.
%K A307607 nonn
%O A307607 1,2
%A A307607 _Ilya Gutkovskiy_, Apr 18 2019