OFFSET
0,2
COMMENTS
Vertex-labeled disconnected Goldstone diagrams with n vertices and k single-particle potentials.
LINKS
P. J. Rossky, M. Karplus, The enumeration of Goldstone diagrams in many-body perturbation theory, J. Chem. Phys. 64 (1976) 1569, equation (9) and Table 1.
FORMULA
T(n,k)= binomial(n,k)*(2*n-k)!.
EXAMPLE
The triangle starts
1;
2 1;
24 12 2;
720 360 72 6;
40320 20160 4320 480 24;
MAPLE
MATHEMATICA
Table[Binomial[n, k](2n-k)!, {n, 0, 10}, {k, 0, n}]//Flatten (* Harvey P. Dale, Feb 03 2022 *)
CROSSREFS
KEYWORD
AUTHOR
R. J. Mathar, Oct 28 2019
STATUS
approved