OFFSET
0,2
LINKS
Colin Barker, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (6,-13,12,-4).
FORMULA
a(n) = 6*a(n-1)-13*a(n-2)+12*a(n-3)-4*a(n-4). - Colin Barker, Dec 04 2014
G.f.: (4*x^2-3*x+1) / ((x-1)^2*(2*x-1)^2). - Colin Barker, Dec 04 2014
a(n) = 2^(n+1)*(n-2) + 2*n + 5. - Christian Krause, Oct 31 2023
MATHEMATICA
LinearRecurrence[{6, -13, 12, -4}, {1, 3, 9, 27}, 40] (* Harvey P. Dale, Aug 13 2015 *)
PROG
(PARI) Vec((4*x^2-3*x+1)/((x-1)^2*(2*x-1)^2) + O(x^100)) \\ Colin Barker, Dec 04 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
Corrected by T. D. Noe, Nov 08 2006
STATUS
approved