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 A185894 #14 Feb 16 2025 08:33:13 %S A185894 0,0,1,1,1,1,2,1,3,1,2,1,2,1,2,2,4,1,2,2,1,2,2,2,1,4,1,2,1,2,1,3,1 %N A185894 Number of prime divisors (counted with multiplicity) of number of rings with n elements. %C A185894 By convention, there is 1 ring with no elements. The first value that I don't know is a(32), where the number of rings with 32 elements was said by Christof Noebauer in 2000 to be > 18590. The next value not known to me is a(64), which is where the same source gives the number of rings with 64 elements > 829826. The articles by Christof Noebauer are linked to from A027623. %H A185894 Eric W. Weisstein <a href="https://mathworld.wolfram.com/Ring.html">Ring</a> %F A185894 a(n) = A001222(A027623(n)). %e A185894 a(16) = 4 because there are A027623(16) = 390 rings with 16 elements, and 390 = 2 * 3 * 5 * 13 has 4 prime divisors counted with multiplicity (in this example, each has multiplicity of 1). %Y A185894 Cf. A001222, A027623. %K A185894 nonn,more,hard %O A185894 0,7 %A A185894 _Jonathan Vos Post_, Feb 05 2011