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
KEYWORD
nonn,easy
AUTHOR
Alois P. Heinz, Apr 30 2023
STATUS
approved