A032174 Number of series-reduced planted compound windmills with n leaves of 2 colors with no symmetries.

2, 1, 4, 15, 66, 291, 1368, 6555, 32262, 161505, 821280, 4227710, 21996052, 115469442, 610894004, 3253836785, 17434360442, 93907348819, 508194420136, 2761768079091, 15065823780102, 82469439357341

Offset: 1

Author

Christian G. Bower

Keywords

• nonn

Links

• Andrew Howroyd, Table of n, a(n) for n = 1..200
• Index entries for sequences related to mobiles

Programs

PARI

CHK(p,n)={sum(d=1, n, moebius(d)/d*log(subst(1/(1+O(x*x^(n\d))-p), x, x^d)))}
seq(n)={my(p=2*x); for(i=2, n, p+=x^i*polcoeff(CHK(p,i),i)); Vecrev(p/x)} \\ Andrew Howroyd, Jun 21 2018

Formula

Doubles (index 2+) under "CHK" (necklace, identity, unlabeled) transform.