OFFSET
0,2
LINKS
Colin Barker, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (1,2,2,2,-1,-1).
FORMULA
G.f.: (1+2*x+4*x^2+10*x^3+28*x^4-8*x^5-14*x^6-6*x^8+3*x^10) / ((1+x)*(1-2*x-2*x^3+x^5)). - Colin Barker, Oct 27 2016
a(n) = a(n-1) + 2*a(n-2) + 2*a(n-3) + 2*a(n-4) - a(n-5) - a(n-6).
a(n) = A242317(n-4) * 6.
MATHEMATICA
Join[{1, 3, 9, 27, 81}, LinearRecurrence[{1, 2, 2, 2, -1, -1}, {150, 366, 870, 2022, 4686, 10974}, 30]] (* Harvey P. Dale, Apr 04 2015 *)
PROG
(PARI) Vec((1+2*x+4*x^2+10*x^3+28*x^4-8*x^5-14*x^6-6*x^8+3*x^10)/((1+x)*(1-2*x-2*x^3+x^5)) + O(x^30)) \\ Colin Barker, Oct 27 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Andrew Woods, Jan 12 2015
EXTENSIONS
Changed offset to 0. - N. J. A. Sloane, Jan 15 2015
STATUS
approved