A032161 - OEIS

%I #14 Sep 20 2018 16:32:41

%S 2,2,3,7,18,48,145,444,1393,4507,14759,49142,165317,562091,1925899,

%T 6647608,23092972,80660663,283138682,998248096,3533524793,12552572322,

%U 44737515682,159919954982,573214555207,2059779884427

%N Number of rooted compound windmills with n nodes and leaves of 2 colors where any 2 submills extending from the same node are different.

%H Andrew Howroyd, <a href="/A032161/b032161.txt">Table of n, a(n) for n = 1..200</a>

%H C. G. Bower, <a href="/transforms2.html">Transforms (2)</a>

%H <a href="/index/Mo#mobiles">Index entries for sequences related to mobiles</a>

%F Shifts left under "CGK" (necklace, element, unlabeled) transform.

%o (PARI)

%o 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))}

%o seq(n)={my(v=[2]); for(i=2, n, v=concat([2], CGK(v))); v} \\ _Andrew Howroyd_, Sep 20 2018

%K nonn

%O 1,1

%A _Christian G. Bower_