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 A362643 #7 Apr 30 2023 23:16:43 %S A362643 1,1,2,10,94,1636,49636,2489824,204626528,27296455456,5930440245856, %T A362643 2144594499551296,1333437360189448768,1510196144261999035648, %U A362643 3333925936841219018864384,15357830414682103475484461056,155003843551785210349182746546176 %N A362643 Number of labeled magmas with n elements satisfying the equations (xy)y = x and x(yz) = xy. %H A362643 Andrew Howroyd, <a href="/A362643/b362643.txt">Table of n, a(n) for n = 0..50</a> %F A362643 E.g.f.: Sum_{k>=0} log(B(k,x))^k/k! where B(k,x) = Sum_{j>=0} A000085(j)^k*x^j/j!. %o A362643 (PARI) %o A362643 B(n, k)=my(p=serlaplace(exp(x + x^2/2 + O(x*x^n)))); sum(j=0, n, polcoef(p,j)^k*x^j/j!, O(x*x^n)) %o A362643 seq(n)=Vec(serlaplace(sum(k=0, n, log(B(n-k+1, k))^k/k!))) %Y A362643 Cf. A000085, A362383, A362386, A362642 (isomorphism classes). %K A362643 nonn %O A362643 0,3 %A A362643 _Andrew Howroyd_, Apr 28 2023