OFFSET
1,2
COMMENTS
A rooted Greg hypertree is a hypertree with black and white vertices such that white vertices are labeled, black vertices are unlabeled, and each black vertex has at least two children.
See A048160 for the analog sequence for Greg trees.
LINKS
Paul Laubie, Hypertrees and embedding of the FMan operad, arXiv:2401.17439 [math.QA], 2024.
FORMULA
EXAMPLE
Triangle T(n,k) begins:
n\k 0 1 2 3 4 ...
1 1;
2 3, 1;
3 19, 16, 3;
4 189, 268, 115, 15;
5 2576, 5221, 3655, 1050, 105;
...
PROG
(PARI) T(n)={my(x='x+O('x^(n+1))); [Vecrev(p) | p <- Vec(serlaplace(serreverse( (log(1+x) - y*exp(x) + y*x + y)*exp(-x) )))]}
{ my(A=T(8)); for(i=1, #A, print(A[i])) } \\ Andrew Howroyd, Mar 06 2024
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Paul Laubie, Mar 06 2024
STATUS
approved