OFFSET
0,2
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (-4,6).
FORMULA
G.f.: (1 - 2*x)/(1 + 4*x - 6*x^2).
a(n) = Sum_{k=0..n} A147703(n,k)*(-7)^k.
a(n) = (1/2)*((-2 - sqrt(10))^n + (-2 + sqrt(10))^n) + (1/5)*sqrt(10)*((-2 - sqrt(10))^n - (-2 + sqrt(10))^n). - Bruno Berselli, Jan 12 2012
MATHEMATICA
LinearRecurrence[{-4, 6}, {1, -6}, 23] (* Bruno Berselli, Jan 12 2012 *)
PROG
(PARI) Vec((1-2*x)/(1+4*x-6*x^2)+O(x^99)) \\ Charles R Greathouse IV, Jan 12 2012
(Haskell)
a152223 n = a152223_list !! n
a152223_list = 1 : -6 : zipWith (-)
(map (* 6) $ a152223_list) (map (* 4) $ tail a152223_list)
-- Reinhard Zumkeller, Jan 12 2012
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Philippe Deléham, Nov 29 2008
EXTENSIONS
a(17)-a(23) corrected by Charles R Greathouse IV, Jan 12 2012
STATUS
approved