A028451 Number of perfect matchings in graph P_{2} X P_{7} X P_{n}.

1, 21, 6272, 880163, 152526845, 24972353440, 4161756233501, 690427159718433, 114725843769441312, 19056798015394695543, 3165986817537284900809, 525966380704787334395776, 87380576637559587656345353, 14516824056706613915897809761, 2411733911295546238838103099168

Offset

0,2

Comments

This sequence satisfies a recurrence relation of order 750. - Sergey Perepechko, Jul 11 2019

Links

Alois P. Heinz, Table of n, a(n) for n = 0..450

Per Hakan Lundow, Computation of matching polynomials and the number of 1-factors in polygraphs, Research report, No 12, 1996, Department of Math., Umea University, Sweden.

Per Hakan Lundow, Enumeration of matchings in polygraphs, 1998.

A. M. Karavaev and S. N. Perepechko, Dimer problem on two-layer rectangular grid graph, (in Russian) CMMASS'2013 slides

Sergey Perepechko, Generating function in Maple notation

Crossrefs

Column k=7 of A181206.

Sequence in context: A074053 A220552 A275053 * A178327 A231906 A250063

Adjacent sequences: A028448 A028449 A028450 * A028452 A028453 A028454

Keyword

nonn

Author

Per H. Lundow

Status

approved