OFFSET
0,2
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..500
Index entries for linear recurrences with constant coefficients, signature (3, -1, -3, 2).
FORMULA
From Andrew Howroyd, Aug 10 2018: (Start)
a(n) = 3*a(n-1) - a(n-2) - 3*a(n-3) + 2*a(n-4).
G.f.: (1 - 3*x^2 + x^3)/((1 - x)^2*(1 + x)*(1 - 2*x)).
(End)
a(n) = Sum_{k=1..n+1} C(n+1,k)^(k mod 2). - Wesley Ivan Hurt, Nov 20 2021
PROG
(PARI) a(n)=2^n + (n+1)\2; \\ Andrew Howroyd, Aug 10 2018
(PARI) Vec((1 - 3*x^2 + x^3)/((1 - x)^2*(1 + x)*(1 - 2*x)) + O(x^40)) \\ Andrew Howroyd, Aug 10 2018
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Gary W. Adamson, Oct 29 2007
EXTENSIONS
Name changed, a(8) inserted and a(14)-a(33) from Andrew Howroyd, Aug 10 2018
STATUS
approved