The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A166964 Number of n-colorings of the Errera graph. 2
0, 0, 0, 0, 960, 4669200, 1342968480, 96351366720, 2967164565120, 51747096270240, 600189633086400, 5123179804311360, 34443698001387840, 191288688014664240, 908558913657114720, 3788089202221833600, 14145018198653072640, 48056437943548695360 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,5
COMMENTS
The Errera graph is a planar graph on 17 vertices and 45 edges with chromatic number 4.
LINKS
Marc Timme, Frank van Bussel, Denny Fliegner, and Sebastian Stolzenberg, Counting complex disordered states by efficient pattern matching: chromatic polynomials and Potts partition functions, New J. Phys. 11 023001 (2009).
Eric Weisstein's World of Mathematics, Errera Graph.
Eric Weisstein's World of Mathematics, Chromatic Polynomial.
Index entries for linear recurrences with constant coefficients, signature (18, -153, 816, -3060, 8568, -18564, 31824, -43758, 48620, -43758, 31824, -18564, 8568, -3060, 816, -153, 18, -1).
FORMULA
a(n) = n^17 - 45*n^16 + ... (see Maple program).
MAPLE
a:= n-> n^17 -45*n^16 +960*n^15 -12900*n^14 +122327*n^13 -868834*n^12 +4785355*n^11 -20863215*n^10 +72791543*n^9 -203886157*n^8 +456534224*n^7 -807157880*n^6 +1101393064*n^5 -1116652249*n^4 +788961246*n^3 -344673280*n^2 +69525840*n:
seq(a(n), n=0..20);
MATHEMATICA
a[n_] := n^17 - 45*n^16 + 960*n^15 - 12900*n^14 + 122327*n^13 - 868834*n^12 + 4785355*n^11 - 20863215*n^10 + 72791543*n^9 - 203886157*n^8 + 456534224*n^7 - 807157880*n^6 + 1101393064*n^5 - 1116652249*n^4 + 788961246*n^3 - 344673280*n^2 + 69525840*n; Table[a[n], {n, 0, 10}] (* G. C. Greubel, May 29 2016 *)
CROSSREFS
Sequence in context: A278011 A282012 A147883 * A316337 A274120 A063797
KEYWORD
nonn,easy
AUTHOR
Alois P. Heinz, Oct 25 2009
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 27 02:22 EDT 2024. Contains 372847 sequences. (Running on oeis4.)