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A295906
Number of (not necessarily maximal) cliques in the n X n king graph.
0
2, 16, 50, 104, 178, 272, 386, 520, 674, 848, 1042, 1256, 1490, 1744, 2018, 2312, 2626, 2960, 3314, 3688, 4082, 4496, 4930, 5384, 5858, 6352, 6866, 7400, 7954, 8528, 9122, 9736, 10370, 11024, 11698, 12392, 13106, 13840, 14594, 15368, 16162, 16976, 17810, 18664, 19538
OFFSET
1,1
LINKS
Eric Weisstein's World of Mathematics, Clique
Eric Weisstein's World of Mathematics, King Graph
FORMULA
a(n) = 2*(5*n^2 - 8*n + 4).
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3).
G.f.: -2*x*(1 + 5*x + 4*x^2)/(-1 + x)^3.
MATHEMATICA
Table[2 (5 n^2 - 8 n + 4), {n, 20}]
LinearRecurrence[{3, -3, 1}, {2, 16, 50}, 20]
CoefficientList[Series[-2 (1 + 5 x + 4 x^2)/(-1 + x)^3, {x, 0, 20}], x]
CROSSREFS
Sequence in context: A232209 A012180 A058376 * A120948 A090453 A006885
KEYWORD
nonn,easy
AUTHOR
Eric W. Weisstein, Nov 29 2017
STATUS
approved