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.
%I A366617 #10 Jul 03 2024 08:59:39
%S A366617 3,12,42,312,942,6264,25284,162000,620460,4961280,16161768,103442688,
%T A366617 367381884,2441936064,9859525284,76963663296,228970112844,
%U A366617 1526377433328,6339280635408,38199227335200,144103649734968,1285221510144000,3894650946433800,24349131482713344
%N A366617 Sum of the divisors of 5^n+1.
%H A366617 Max Alekseyev, <a href="/A366617/b366617.txt">Table of n, a(n) for n = 0..471</a>
%F A366617 a(n) = sigma(5^n+1) = A000203(A034474(n)).
%e A366617 a(3)=312 because 5^3+1 has divisors {1, 2, 3, 6, 7, 9, 14, 18, 21, 42, 63, 126}.
%p A366617 a:=n->numtheory[sigma](5^n+1):
%p A366617 seq(a(n), n=0..100);
%t A366617 DivisorSigma[1, 5^Range[0, 30] + 1] (* _Paolo Xausa_, Jul 03 2024 *)
%Y A366617 Cf. A000203, A034474, A057939, A074478, A366613, A366615, A366616, A366618.
%Y A366617 Cf. A069061, A366578, A366607, A366629, A366638, A366657, A366666, A366668, A366689, A366715.
%K A366617 nonn
%O A366617 0,1
%A A366617 _Sean A. Irvine_, Oct 14 2023