OFFSET
1,1
LINKS
Index entries for linear recurrences with constant coefficients, signature (1,0,1,-1).
FORMULA
G.f.: x*(1+x)*(x^2+3) / ((1+x+x^2)*(x-1)^2). - R. J. Mathar, Oct 08 2011
From Wesley Ivan Hurt, Jun 10 2016: (Start)
a(n) = a(n-1) + a(n-3) - a(n-4) for n>4.
a(n) = (24*n-9*cos(2*n*Pi/3)-sqrt(3)*sin(2*n*Pi/3))/9.
a(3k) = 8k-1, a(3k-1) = 8k-2, a(3k-2) = 8k-5. (End)
MAPLE
A047556:=n->(24*n-9*cos(2*n*Pi/3)-sqrt(3)*sin(2*n*Pi/3))/9: seq(A047556(n), n=1..100); # Wesley Ivan Hurt, Jun 10 2016
MATHEMATICA
Select[Range[0, 150], MemberQ[{3, 6, 7}, Mod[#, 8]] &] (* Wesley Ivan Hurt, Jun 10 2016 *)
LinearRecurrence[{1, 0, 1, -1}, {3, 6, 7, 11}, 60] (* Harvey P. Dale, Sep 02 2024 *)
PROG
(Magma) [n : n in [0..150] | n mod 8 in [3, 6, 7]]; // Wesley Ivan Hurt, Jun 10 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved