A159056 Number of n-colorings of the Clebsch Graph.

0, 0, 0, 0, 28560, 18277200, 1925512560, 71729634480, 1389478980960, 17119717947360, 151217975815200, 1034656343471520, 5783087147848560, 27431854405990320, 113598910323858960, 419654992044834000, 1406448998999378880, 4333949766504066240, 12412819895060854080

Offset

0,5

Comments

The Clebsch Graph or Greenwood-Gleason Graph is a strongly regular quintic graph on 16 vertices and 40 edges.

Links

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.

Eric Weisstein's World of Mathematics, Clebsch Graph

Eric Weisstein's World of Mathematics, Chromatic Polynomial

Index entries for linear recurrences with constant coefficients, signature (17, -136, 680, -2380, 6188, -12376, 19448, -24310, 24310, -19448, 12376, -6188, 2380, -680, 136, -17, 1).

Formula

a(n) = n^16 -40*n^15 + ... (see Maple program).

Maple

a:= n-> n^16 -40*n^15 +780*n^14 -9840*n^13 +89718*n^12 -624856*n^11 +3423400*n^10 -14966420*n^9 +52409081*n^8 -146275504*n^7 +320950404*n^6 -540248540*n^5 +670404830*n^4 -573961940*n^3 +299904066*n^2 -71095140*n:
seq(a(n), n=0..25);

Crossrefs

Sequence in context: A253837 A253844 A253931 * A017536 A013869 A256841

Adjacent sequences: A159053 A159054 A159055 * A159057 A159058 A159059

Keyword

nonn,easy

Author

Alois P. Heinz, Apr 03 2009

Status

approved