OFFSET
1,2
LINKS
FORMULA
G.f.: x*(2 - x)/((1 - x)*(1 + 2*x)*(1 - 3*x)). - Andrew Howroyd, Jun 15 2021
EXAMPLE
a(4) = (1/6)*(3^4 + (-2)^4 - 1) = (1/6)*(81+16-1) = 16.
MATHEMATICA
LinearRecurrence[{2, 5, -6}, {0, 2, 3}, 30] (* Greg Dresden, Jun 19 2021 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Ryan Brooks, Jun 14 2021
STATUS
approved