%I #9 Sep 13 2018 03:05:31
%S 1,1,2,5,8,18,40,77,180,378,822,1750,3824,8016,16630,36100,74092,
%T 154325,317388,657064,1348688,2732441,5554850,11203449,22725376,
%U 45309407,90568158,180428451,358348728,709098028,1395536060
%N "BGK" (reversible, element, unlabeled) transform of 1,2,3,4,...
%H Andrew Howroyd, <a href="/A032063/b032063.txt">Table of n, a(n) for n = 0..1000</a>
%H C. G. Bower, <a href="/transforms2.html">Transforms (2)</a>
%o (PARI) seq(n)=[subst(serlaplace(y^0*p + polcoeff(p,1)),y,1)/2 | p <- Vec(y-1+prod(k=1, n, (1 + x^k*y + O(x*x^n))^k))] \\ _Andrew Howroyd_, Sep 13 2018
%K nonn
%O 0,3
%A _Christian G. Bower_
%E a(0)=1 prepended by _Andrew Howroyd_, Sep 13 2018