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 A323600 #21 Feb 06 2019 09:15:26
%S A323600 0,1,1,4,1,9,1,11,5,11,1,31,1,13,12,26,1,38,1,39,14,17,1,81,7,19,18,
%T A323600 47,1,83,1,57,18,23,16,127,1,25,20,103,1,101,1,63,53,29,1,187,9,66,24,
%U A323600 71,1,130,20,125,26,35,1,272,1,37,63,120,22,137,1,87,30,127,1
%N A323600 Dirichlet convolution of sigma with omega.
%C A323600 a(n) = omega(n) = 1 iff n is prime.
%C A323600 Not all positive integers are terms of this sequence as many are not expressible as the sum of products defined by the sequence, for example 2, 3, and 6.
%H A323600 Alois P. Heinz, <a href="/A323600/b323600.txt">Table of n, a(n) for n = 1..10000</a>
%H A323600 Wikipedia, <a href="https://en.wikipedia.org/wiki/Dirichlet_convolution">Dirichlet convolution</a>
%F A323600 a(n) = Sum_{d|n} A000203(d) * A001221(n/d).
%p A323600 with(numtheory):
%p A323600 a:= n-> add(sigma(d)*nops(factorset(n/d)), d=divisors(n)):
%p A323600 seq(a(n), n=1..100); # _Alois P. Heinz_, Jan 28 2019
%t A323600 Table[DivisorSum[n, DivisorSigma[1, #] PrimeNu[n/#] &], {n, 71}] (* _Michael De Vlieger_, Jan 27 2019 *)
%o A323600 (PARI) a(n) = sumdiv(n, d, sigma(d)*omega(n/d)); \\ _Michel Marcus_, Jan 22 2019
%Y A323600 Cf. A000203, A001221.
%K A323600 nonn
%O A323600 1,4
%A A323600 _Torlach Rush_, Jan 18 2019