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 A365633 #12 Sep 20 2023 01:44:24
%S A365633 1,1,1,3,1,1,1,3,1,1,1,3,1,1,1,7,1,1,1,3,1,1,1,3,1,1,4,3,1,1,1,7,1,1,
%T A365633 1,3,1,1,1,3,1,1,1,3,1,1,1,7,1,1,1,3,1,4,1,3,1,1,1,3,1,1,1,15,1,1,1,3,
%U A365633 1,1,1,3,1,1,1,3,1,1,1,7,4,1,1,3,1,1,1
%N A365633 The sum of divisors of n that are terms of A072873.
%C A365633 The number of these divisors is A365632(n) and the largest of them is A327939(n).
%H A365633 Amiram Eldar, <a href="/A365633/b365633.txt">Table of n, a(n) for n = 1..10000</a>
%F A365633 Multiplicative with a(p^e) = (p^(floor(e/p)+1) - 1)/(p - 1).
%F A365633 Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k) = Product_{p prime} (A332653(p)/(p^(p-1)-1) - 1/(p*(p-1))) = 2.253624924813... .
%t A365633 f[p_, e_] := (p^(Floor[e/p] + 1) - 1)/(p - 1); a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100]
%o A365633 (PARI) a(n) = {my(f = factor(n)); prod(i = 1, #f~, (f[i,1]^(1+f[i,2] \ f[i,1])-1)/(f[i,1] - 1));}
%Y A365633 Cf. A072873, A327939, A332653, A365632.
%K A365633 nonn,easy,mult
%O A365633 1,4
%A A365633 _Amiram Eldar_, Sep 14 2023