A032201 - OEIS

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A032201

Number of rooted compound windmills with n nodes and leaves of 2 colors.

2, 2, 5, 13, 40, 128, 457, 1660, 6308, 24409, 96363, 385535, 1561706, 6387135, 26347199, 109471366, 457758461, 1924845582, 8134171456, 34526723986, 147139513066, 629314845284, 2700401538933, 11622130671430

(list; graph; refs; listen; history; text; internal format)

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 "CIK" (necklace, indistinct, unlabeled) transform.

PROG

(PARI)

CIK(p, n)={sum(d=1, n, eulerphi(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+CIK(x*p, i)); Vec(p)} \\ Andrew Howroyd, Jun 20 2018

CROSSREFS

Sequence in context: A029856 A072898 A032290 * A268180 A268003 A208434

Adjacent sequences: A032198 A032199 A032200 * A032202 A032203 A032204

KEYWORD

nonn

AUTHOR

Christian G. Bower

STATUS

approved