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A166964
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Number of n-colorings of the Errera graph.
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2
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0, 0, 0, 0, 960, 4669200, 1342968480, 96351366720, 2967164565120, 51747096270240, 600189633086400, 5123179804311360, 34443698001387840, 191288688014664240, 908558913657114720, 3788089202221833600, 14145018198653072640, 48056437943548695360
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OFFSET
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0,5
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COMMENTS
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The Errera graph is a planar graph on 17 vertices and 45 edges with chromatic number 4.
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LINKS
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Alois P. Heinz, Table of n, a(n) for n = 0..1000
Timme, Marc; van Bussel, Frank; Fliegner, Denny; Stolzenberg, Sebastian (2009) "Counting complex disordered states by efficient pattern matching: chromatic polynomials and Potts partition functions", New J. Phys. 11 023001, doi: 10.1088/1367-2630/11/2/023001.
Weisstein, Eric W. "Errera Graph".
Weisstein, Eric W. "Chromatic Polynomial".
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FORMULA
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a(n) = n^17 -45*n^16 + ... (see Maple program).
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MAPLE
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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);
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CROSSREFS
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Sequence in context: A203732 A157851 A147883 * A063797 A098207 A158414
Adjacent sequences: A166961 A166962 A166963 * A166965 A166966 A166967
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KEYWORD
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nonn
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AUTHOR
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Alois P. Heinz, Oct 25 2009
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STATUS
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approved
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