A158904 Number of n-colorings of the Hoffman graph.

0, 0, 2, 2970, 1346052, 190310900, 10284101190, 270774275982, 4231630881800, 44940276612072, 355458410080650, 2231437465657730, 11635407170995212, 52110833436028380, 205595759294267342, 728666611701477750, 2355900976191279120, 7034807710363658192

Offset

0,3

Comments

The Hoffman graph has 16 vertices and 32 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.

Weisstein, Eric W. "Hoffman Graph".

Weisstein, Eric W. "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).

Maple

a:= n-> n^16 -32*n^15 +496*n^14 -4936*n^13 +35268*n^12 -191692*n^11 +819004*n^10 -2801044*n^9 +7728104*n^8 -17178976*n^7 +30442928*n^6 -42072224*n^5 +43650458*n^4 -31857932*n^3 +14483632*n^2 -3053055*n:
seq(a(n), n=0..20);

Crossrefs

Sequence in context: A128148 A308575 A158348 * A358177 A175080 A243649

Adjacent sequences: A158901 A158902 A158903 * A158905 A158906 A158907

Keyword

nonn,easy

Author

Alois P. Heinz, Mar 29 2009

Status

approved