OFFSET
0,6
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..1000
C. G. Bower, Transforms (2)
FORMULA
"CGK" (necklace, element, unlabeled) transform of 0, 1, 1, 1, ...
G.f.: 1 + Sum_{k>=1} (k-1)! * x^((k^2+3*k)/2) / (Product_{j=1..k} 1-x^j). - Andrew Howroyd, Sep 13 2018
PROG
(PARI) seq(n)=[subst(serlaplace(p/y*y^0), y, 1) | p <- Vec(y-1+prod(k=2, n, 1 + x^k*y + O(x*x^n)))] \\ Andrew Howroyd, Sep 13 2018
(PARI) seq(n)={Vec(1 + sum(k=1, n, my(r=(k^2+3*k)/2); if(r<=n, (k-1)! * x^r / prod(j=1, k, 1 - x^j + O(x*x^(n-r))))))} \\ Andrew Howroyd, Sep 13 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
a(0)=1 prepended by Andrew Howroyd, Sep 13 2018
STATUS
approved