OFFSET
0,2
COMMENTS
Apart from sign, same as A001079 (see first formula).
LINKS
FORMULA
a(n) = (-1)^n A001079(n).
From Colin Barker, Oct 26 2014: (Start)
a(n) = ((-5-2*sqrt(6))^n+(-5+2*sqrt(6))^n)/2.
a(n) = -10*a(n-1)-a(n-2).
G.f.: (5*x+1) / (x^2+10*x+1).
(End)
MATHEMATICA
Table[Round[N[Cos[2 n ArcSin[Sqrt[3]]], 50]], {n, 0, 100}]
PROG
(PARI) Vec((5*x+1)/(x^2+10*x+1) + O(x^100)) \\ Colin Barker, Oct 26 2014
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Artur Jasinski, Oct 29 2008
EXTENSIONS
a(18) from Colin Barker, Oct 26 2014
STATUS
proposed