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 A333751 #11 Sep 12 2024 17:34:22
%S A333751 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,5,1,1,1,5,1,1,1,5,1,1,1,5,1,1,1,5,1,1,
%T A333751 1,11,1,1,1,5,1,7,1,5,1,1,1,11,1,1,1,5,1,7,1,5,1,1,1,11,1,1,1,13,1,7,
%U A333751 1,5,1,1,1,19,1,1,1,5,1,7,1,13,10,1,1,11,1,1,1,13,1,16
%N A333751 Sum of nonprime divisors of n that are <= sqrt(n).
%H A333751 Robert Israel, <a href="/A333751/b333751.txt">Table of n, a(n) for n = 1..10000</a>
%F A333751 G.f.: Sum_{k>=1} A018252(k) * x^(A018252(k)^2) / (1 - x^A018252(k)).
%p A333751 f:= proc(n) convert(select(t -> not isprime(t) and t^2 <= n, numtheory:-divisors(n)),`+`) end proc:
%p A333751 map(f, [$1..100]); # _Robert Israel_, Sep 12 2024
%t A333751 Table[DivisorSum[n, # &, # <= Sqrt[n] && !PrimeQ[#] &], {n, 1, 90}]
%t A333751 nmax = 90; CoefficientList[Series[Sum[Boole[!PrimeQ[k]] k x^(k^2)/(1 - x^k), {k, 1, nmax}], {x, 0, nmax}], x] // Rest
%o A333751 (PARI) a(n) = sumdiv(n, d, if ((d^2<=n) && !isprime(d), d)); \\ _Michel Marcus_, Apr 03 2020
%Y A333751 Cf. A018252, A023890, A066839, A069289, A069293, A097974, A333748, A333752, A333753.
%K A333751 nonn
%O A333751 1,16
%A A333751 _Ilya Gutkovskiy_, Apr 03 2020