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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
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