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 A307100 #14 Mar 23 2025 17:03:17
%S A307100 1,5,7,29,11,155,15,285,88,415,23,10547,27,803,917,5405,35,35228,39,
%T A307100 48439,1785,1963,47,2665011,386,2735,3004,132539,59,6481465,63,202013,
%U A307100 4385,4663,4925,90744884,75,5819,6117,20528695,83,24896285,87,513091,547748,8515
%N A307100 a(n) = Sum_{d|n} (tau(d)*pod(d)) where tau(k) = the number of divisors of k (A000005) and pod(k) = the product of the divisors of k (A007955).
%C A307100 n divides a(n) for n = 1, 21, 333592, ...
%F A307100 a(p) = 2*(p+1) for p = primes (A000040).
%e A307100 a(6) = tau(1)*pod(1) + tau(2)*pod(2) + tau(3)*pod(3) + tau(6)*pod(6) = (1*1) + (2*2) + (2*3) + (4*36) = 155.
%o A307100 (Magma) [&+[# [c: c in Divisors(d)] * &*[c: c in Divisors(d)]: d in Divisors(n)]: n in [1..100]];
%o A307100 (PARI) a(n) = sumdiv(n, d, my(dd=divisors(d)); #dd*vecprod(dd)); \\ _Michel Marcus_, Apr 25 2019
%Y A307100 Cf. A000005, A007955, A307101.
%K A307100 nonn
%O A307100 1,2
%A A307100 _Jaroslav Krizek_, Apr 25 2019