A158792 Number of n-colorings of the Shrikhande graph.

0, 0, 0, 0, 240, 332400, 105480720, 7787433360, 233556076320, 3881511113760, 42569914312800, 342908176422240, 2176503575487120, 11428762115181840, 51423745096804080, 203533610650297200, 722989464927562560, 2341382980699049280, 6999973732130650560

Offset: 0

Author

Alois P. Heinz, Mar 26 2009

Keywords

• nonn
• easy

Comments

The Shrikhande graph has 16 vertices and 48 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. "Shrikhande 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 -48*n^15 +1096*n^14 -15812*n^13 +161320*n^12 -1233064*n^11 +7290402*n^10 -33903652*n^9 [phone]*n^8 -362020596*n^7 [phone]*n^6 -1407982096*n^5 [phone]*n^4 -1531612072*n^3 [phone]*n^2 -190557420*n:
seq(a(n), n=0..20);

Formula

a(n) = n^16 -48*n^15 + ... (see Maple program).