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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A050402 Number of independent sets of nodes in C_4 X C_n (n > 2). 1
7, 1, 35, 121, 743, 3561, 18995, 96433, 500871, 2573905, 13292995, 68492073, 353290343, 1821383097, 9392360019, 48428332641, 249716406791, 1287608913057, 6639354593123, 34234612471001, 176524935990503, 910219628918665, 4693389213891699, 24200638961917201 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

REFERENCES

C. Bautista-Ramos and C. Guillen-Galvan, Fibonacci numbers of generalized Zykov sums, J. Integer Seq., 15 (2012), Article 12.7.8

LINKS

Colin Barker, Table of n, a(n) for n = 0..1000

Eric Weisstein's World of Mathematics, Independent Vertex Set

Eric Weisstein's World of Mathematics, Torus Grid Graph

Index entries for linear recurrences with constant coefficients, signature (2,15,8,-7,-2,1).

FORMULA

a(n) = a(n-1) + 17*a(n-2) + 23*a(n-3) + a(n-4) - 9*a(n-5) - a(n-6) + a(n-7).

G.f.: -(x^5 +17*x^4 -20*x^3 -72*x^2 -13*x +7)/((x +1)*(x^2 -2*x -1)*(x^3 -x^2 -5*x +1)). - Colin Barker, Aug 31 2012

PROG

(PARI) Vec((7 - 13*x - 72*x^2 - 20*x^3 + 17*x^4 + x^5) / ((1 + x)*(1 + 2*x - x^2)*(1 - 5*x - x^2 + x^3)) + O(x^30)) \\ Colin Barker, May 11 2017

CROSSREFS

Sequence in context: A002678 A147482 A171770 * A027643 A225122 A051931

Adjacent sequences:  A050399 A050400 A050401 * A050403 A050404 A050405

KEYWORD

easy,nonn

AUTHOR

Stephen G. Penrice (spenrice(AT)ets.org), Dec 21 1999

EXTENSIONS

More terms from Michael Lugo (mlugo(AT)thelabelguy.com), Dec 22 1999

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 February 21 07:18 EST 2018. Contains 299390 sequences. (Running on oeis4.)