A328921 Triangle read by rows: T(n,k) = number of vertex labeled connected Goldstone diagrams with n interactions and k external potentials.

1, 2, 1, 20, 8, 1, 592, 240, 36, 2, 33888, 14208, 2400, 192, 6, 3134208, 1355520, 248640, 24000, 1200, 24, 423974400, 188052480, 36599040, 3978240, 252000, 8640, 120, 78722795520, 35613849600, 7240020480, 853977600, 62657280, 2822400, 70560, 720, 19193652817920, 8816953098240, 1851920179200

Offset: 0

Author

R. J. Mathar, Oct 31 2019

Keywords

• nonn
• tabl

Examples

			          1;
          2           1;
         20           8           1;
        592         240          36           2;
      33888       14208        2400         192           6;
    3134208     1355520      248640       24000        1200          24;
		

Links

• R. J. Mathar, Maple program computing A328921 - A328924.
• P. J. Rossky and M. Karplus, The enumeration of Goldstone diagrams in many-body perturbation theory, J. Chem. Phys. 64 (1976) 1569, C(n,k)

Crossrefs

Cf. A328922, A328923, A328924.

Formula

T(n,k) + A328922(n,k) = A328826(n,k).