A032172 Number of rooted compound windmills with n nodes and leaves of 2 colors with no symmetries.

2, 2, 3, 9, 27, 93, 317, 1148, 4203, 15781, 60066, 231968, 905301, 3567982, 14175319, 56722193, 228380002, 924598874, 3761536993, 15370095298, 63051505041, 259573763572, 1072091242996, 4441058718736

Offset

1,1

Links

Andrew Howroyd, Table of n, a(n) for n = 1..200

Index entries for sequences related to mobiles

Formula

Shifts left under "CHK" (necklace, identity, unlabeled) transform.

Prog

(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=O(1)); for(i=1, n, p=2+CHK(x*p, i)); Vec(p)} \\ Andrew Howroyd, Jun 20 2018

Crossrefs

Sequence in context: A275329 A021821 A019234 * A032103 A091044 A079661

Adjacent sequences: A032169 A032170 A032171 * A032173 A032174 A032175

Keyword

nonn

Author

Christian G. Bower

Status

approved