Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #15 Jun 21 2018 10:34:34
%S 1,1,2,5,12,36,104,331,1062,3519,11809,40327,139066,484698,1702819,
%T 6026452,21460248,76846950,276524978,999423375,3626370269,13205135288,
%U 48241233346,176757275833,649399348322,2391817886703
%N Number of series-reduced planted compound windmills with n leaves.
%H Andrew Howroyd, <a href="/A032203/b032203.txt">Table of n, a(n) for n = 1..200</a>
%H <a href="/index/Mo#mobiles">Index entries for sequences related to mobiles</a>
%H INRIA Algorithms Project, <a href="http://ecs.inria.fr/services/structure?nbr=79">Encyclopedia of Combinatorial Structures 79</a>
%F Doubles (index 2+) under "CIK" (necklace, indistinct, unlabeled) transform.
%o (PARI)
%o CIK(p,n)={sum(d=1, n, eulerphi(d)/d*log(subst(1/(1+O(x*x^(n\d))-p), x, x^d)))}
%o seq(n)={my(p=x); for(i=2, n, p+=x^i*polcoeff(CIK(p,i),i)); Vecrev(p/x)} \\ _Andrew Howroyd_, Jun 21 2018
%K nonn
%O 1,3
%A _Christian G. Bower_