A033520 Number of matchings in graph C_{8} X P_{n}.

1, 47, 11396, 2217871, 447264801, 89761235312, 18027314711921, 3620162014192047, 726995373373259268, 145993770068726584623, 29318189070923580394385, 5887622256467996898381824, 1182340968901089528485742513, 237435437338572028041097654463

Offset

0,2

References

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

Links

Alois P. Heinz, Table of n, a(n) for n = 0..400

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

Formula

G.f.: -(x^28 -15*x^27 -284*x^26 +5183*x^25 +5371*x^24 -366892*x^23 +814436*x^22 +8226936*x^21 -29920872*x^20 -57862312*x^19 +331173012*x^18 -7873260*x^17 -1396434310*x^16 +1211992974*x^15 +1877432864*x^14 -2719474366*x^13 -471197866*x^12 +1952262300*x^11 -397859476*x^10 -507235480*x^9 +186066152*x^8 +41696904*x^7 -22010724*x^6 +36860*x^5 +598453*x^4 -36831*x^3 -2052*x^2 +159*x -1) / (x^30 -14*x^29 -430*x^28 +6634*x^27 +38158*x^26 -871958*x^25 +1251837*x^24 +29038240*x^23 -101668292*x^22 -290911416*x^21 +1623376452*x^20 +319719232*x^19 -9632041694*x^18 +7238239524*x^17 +21683751232*x^16 -26978306260*x^15 -17795407872*x^14 +34467592724*x^13 +1093570370*x^12 -17442114832*x^11 +3542012836*x^10 +3435559720*x^9 -1062456996*x^8 -223403632*x^7 +95033757*x^6 -1202342*x^5 -1914226*x^4 +150650*x^3 +338*x^2 -206*x +1). - Alois P. Heinz, Dec 09 2013

Crossrefs

Row 8 of A287428.

Sequence in context: A362714 A267063 A287225 * A210818 A093940 A237512

Adjacent sequences: A033517 A033518 A033519 * A033521 A033522 A033523

Keyword

nonn,easy

Author

Per H. Lundow

Status

approved