A033518 Number of matchings in graph C_{6} X P_{n}.

1, 18, 1104, 57536, 3079253, 164206124, 8761336545, 467431319920, 24938493433976, 1330521524829842, 70986162750517765, 3787263138969145376, 202058564666736227181, 10780255299668629970930, 575149608382918617117024, 30685458073339150537724112

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..500

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

Formula

G.f.: (x^11 -3*x^10 -60*x^9 +252*x^8 +153*x^7 -1427*x^6 +771*x^5 +1007*x^4 -452*x^3 -84*x^2 +35*x -1) / ( -x^13 +5*x^12 +90*x^11 -424*x^10 -1420*x^9 +6022*x^8 +1276*x^7 -14388*x^6 +5806*x^5 +5076*x^4 -2616*x^3 +66*x^2 +53*x -1). - Alois P. Heinz, Dec 09 2013

Crossrefs

Row 6 of A287428.

Sequence in context: A159379 A323571 A052135 * A333006 A064564 A152933

Adjacent sequences: A033515 A033516 A033517 * A033519 A033520 A033521

Keyword

nonn

Author

Per H. Lundow

Status

approved