A362712 Number of n-colorings of the Goldner-Harary graph.

0, 0, 0, 0, 24, 15360, 787320, 13762560, 131250000, 846526464, 4150656720, 16609443840, 56821671720, 171600000000, 468159796104, 1173850030080, 2740855222560, 6021219348480, 12547912500000, 24970939858944, 47714180896440, 87939285396480, 156928122498840

Offset

0,5

Links

Alois P. Heinz, Table of n, a(n) for n = 0..10000

Eric Weisstein's World of Mathematics, Goldner-Harary Graph

Wikipedia, Chromatic polynomial

Wikipedia, Goldner-Harary graph

Index entries for linear recurrences with constant coefficients, signature (12,-66,220,-495,792,-924,792,-495,220,-66,12,-1).

Formula

G.f.: 24*x^4*(16384*x^7 +194017*x^6 +592884*x^5 +612295*x^4 +221800*x^3 +25191*x^2 +628*x +1)/(x-1)^12.

a(n) = n^11 -27*n^10 +326*n^9 -2316*n^8 +10710*n^7 -33642*n^6 +72576*n^5 -105948*n^4 +99873*n^3 -54675*n^2 +13122*n.

Maple

a:= n-> ((((((((((n-27)*n+326)*n-2316)*n+10710)*n-33642)*n
            +72576)*n-105948)*n+99873)*n-54675)*n+13122)*n:
seq(a(n), n=0..25);

Crossrefs

Sequence in context: A341801 A028694 A091777 * A279299 A145496 A279655

Adjacent sequences: A362709 A362710 A362711 * A362713 A362714 A362715

Keyword

nonn,easy

Author

Alois P. Heinz, Apr 30 2023

Status

approved