OFFSET
1,1
LINKS
Eric Weisstein's World of Mathematics, Clique
Eric Weisstein's World of Mathematics, Knight Graph
Index entries for linear recurrences with constant coefficients, signature (3, -3, 1).
FORMULA
a(n) = 5*n^2 - 12*n + 9.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3).
G.f.: x*(-2 + x - 9 x^2)/(-1 + x)^3.
MATHEMATICA
Table[5 n^2 - 12 n + 9, {n, 20}]
LinearRecurrence[{3, -3, 1}, {2, 5, 18}, 20]
CoefficientList[Series[(-2 + x - 9 x^2)/(-1 + x)^3, {x, 0, 20}], x]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Eric W. Weisstein, Nov 29 2017
STATUS
approved