OFFSET
0,2
LINKS
Paolo Xausa, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (4,-3,-2,1).
FORMULA
a(n) = 4*a(n-1)-3*a(n-2)-2*a(n-3)+a(n-4), a(0)=0, a(1)=2, a(2)=6, a(3)=18.
G.f.: 2*x*(1-x)/((1-3*x+x^2)*(1-x-x^2)).
a(n) = 2 * A094292(n+1). - Alois P. Heinz, Apr 07 2023
EXAMPLE
MATHEMATICA
LinearRecurrence[{4, -3, -2, 1}, {0, 2, 6, 18}, 50] (* Paolo Xausa, Jun 10 2024 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Philippe Deléham, Apr 07 2023
STATUS
approved