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

Author

Alois P. Heinz, Mar 29 2009

Keywords

• nonn
• easy

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).

Programs

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 [phone]*n^6 -42072224*n^5 [phone]*n^4 -31857932*n^3 [phone]*n^2 -3053055*n:
seq(a(n), n=0..20);