login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A028481 Number of perfect matchings in graph C_{10} X P_{n}. 1
1, 2, 125, 1452, 37584, 631750, 13344409, 248864088, 4964424625, 95464562688, 1872712598261, 36340255066500, 709361528836661, 13802335712555182, 269027285006250000, 5238744073324512432, 102066374099541816889, 1987998048123941635250, 38727167228395071878789 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

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.

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^16 +8*x^15 -130*x^14 -320*x^13 +3030*x^12 +1910*x^11 -16645*x^10 -5140*x^9 +27980*x^8 +5140*x^7 -16645*x^6 -1910*x^5 +3030*x^4 +320*x^3 -130*x^2 -8*x +1) / (x^18 +10*x^17 -235*x^16 -588*x^15 +8165*x^14 +6430*x^13 -72855*x^12 -40880*x^11 +199465*x^10 +70490*x^9 -199465*x^8 -40880*x^7 +72855*x^6 +6430*x^5 -8165*x^4 -588*x^3 +235*x^2 +10*x -1). - Alois P. Heinz, Dec 10 2013

CROSSREFS

Sequence in context: A183720 A042921 A123006 * A049659 A209602 A237994

Adjacent sequences:  A028478 A028479 A028480 * A028482 A028483 A028484

KEYWORD

nonn

AUTHOR

Per H. Lundow

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 12 01:57 EST 2019. Contains 329948 sequences. (Running on oeis4.)