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

 

Logo

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A028480 Number of perfect matchings in graph C_{9} X P_{2n}. 1
1, 76, 11989, 2091817, 372713728, 66750320449, 11970180565381, 2147314732677364, 385238046548443177, 69115057977256578649, 12399917664600455876068, 2224670061782262303745381, 399128369515444836686385361, 71607684753022827432994707712 (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..400

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

FORMULA

G.f.: (x^15 -189*x^14+9585*x^13 -194987*x^12 +1937034*x^11 -10357902*x^10 +31195513*x^9 -53951967*x^8 +53951967*x^7 -31195513*x^6 +10357902*x^5 -1937034*x^4 +194987*x^3 -9585*x^2 +189*x -1) / ( -x^16 +265*x^15 -17736*x^14 +457655*x^13 -5699687*x^12 +38357160*x^11 -146975161*x^10 +327381265*x^9 -427427424*x^8 +327381265*x^7 -146975161*x^6 +38357160*x^5 -5699687*x^4 +457655*x^3 -17736*x^2 +265*x -1). - Alois P. Heinz, Dec 10 2013

CROSSREFS

Sequence in context: A184290 A093238 A185984 * A229413 A111682 A271242

Adjacent sequences:  A028477 A028478 A028479 * A028481 A028482 A028483

KEYWORD

nonn,easy

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified December 5 03:30 EST 2016. Contains 278755 sequences.