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A032161
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Number of rooted compound windmills with n nodes and leaves of 2 colors where any 2 submills extending from the same node are different.
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1
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2, 2, 3, 7, 18, 48, 145, 444, 1393, 4507, 14759, 49142, 165317, 562091, 1925899, 6647608, 23092972, 80660663, 283138682, 998248096, 3533524793, 12552572322, 44737515682, 159919954982, 573214555207, 2059779884427
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OFFSET
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1,1
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LINKS
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FORMULA
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Shifts left under "CGK" (necklace, element, unlabeled) transform.
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PROG
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(PARI)
CGK(v)={apply(p->subst(serlaplace(p/y), y, 1), Vec(prod(k=1, #v, (1 + x^k*y + O(x*x^#v))^v[k])-1, -#v))}
seq(n)={my(v=[2]); for(i=2, n, v=concat([2], CGK(v))); v} \\ Andrew Howroyd, Sep 20 2018
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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