A057572 Number of unlabeled Hugenholz diagrams with n nodes.

1, 1, 12, 148, 3150, 90075, 3431015, 167013000, 10129020300

Offset

2,3

Comments

Hugenholz diagrams are a way of expressing terms in the quantum mechanical many-body perturbation theory.

References

P. D. Stevenson, "Automatic Generation of Vacuum Amplitude Many-Body Perturbation Series", Int. J. Mod. Phys. C 14, 1135 (2003)

A. Szabo and N. Ostlund, Modern Quantum Chemistry, Dover Publications, New York, 1996

Links

Table of n, a(n) for n=2..10.

Sean A. Irvine, Java program (github)

Crossrefs

Cf. A064732.

Sequence in context: A350655 A167138 A001406 * A114106 A015610 A141326

Adjacent sequences: A057569 A057570 A057571 * A057573 A057574 A057575

Keyword

hard,more,nonn

Author

Paul Stevenson, Nov 28 2000

Extensions

Offset corrected and a(9)-a(10) from Sean A. Irvine, Jun 17 2022

Status

approved