A328923 Triangle T(n,k) read by rows: connected topologies of Goldstone diagrams with n interactions and k external potentials.

1, 2, 1, 6, 4, 1, 76, 60, 18, 2, 2124, 1776, 600, 96, 6, 97968, 84720, 31080, 6000, 600, 24, 6624720, 5876640, 2287440, 497280, 63000, 4320, 120, 615022560, 556466400, 226250640, 53373600, 7832160, 705600, 35280, 720, 74975211360, 68882446080, 28936252800, 7240020480

Offset: 0

Author

R. J. Mathar, Oct 31 2019

Keywords

• nonn
• tabl

Examples

			         1;
         2          1;
         6          4          1;
        76         60         18          2;
      2124       1776        600         96          6;
     97968      84720      31080       6000        600         24;
   6624720    5876640    2287440     497280      63000       4320        120;
		

Links

• P. J. Rossky, M. Karplus, The enumeration of Goldstone diagrams in many-body perturbation theory, J. Chem. Phys. 64 (1976) 1569, T(n,k)

Crossrefs

Cf. A328921-A328924

Formula

T(n,0) = A328921(n,0) / 2^n +(n-1)! .

T(n,k) = 2^(k-n)*A328921(n,k), k>0 .