OFFSET
0,2
COMMENTS
All terms are powers of 2 (see comment in A138377). - Michel Marcus, Dec 01 2015
LINKS
Colin Barker, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (0,0,0,-4).
FORMULA
From Colin Barker, Dec 01 2015: (Start)
a(n) = -4*a(n-4) for n>3.
G.f.: (1-x)*(1+x)*(1+2*x) / ((1-2*x+2*x^2)*(1+2*x+2*x^2)).
(End)
MATHEMATICA
Differences[LinearRecurrence[{0, 0, 0, -4}, {0, 1, 3, 2}, 60]] (* Harvey P. Dale, Mar 19 2012 *)
LinearRecurrence[{0, 0, 0, -4}, {1, 2, -1, -2}, 59] (* Ray Chandler, Aug 03 2015 *)
PROG
(PARI) Vec((1-x)*(1+x)*(1+2*x)/((1-2*x+2*x^2)*(1+2*x+2*x^2)) + O(x^100)) \\ Colin Barker, Dec 01 2015
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Paul Curtz, May 08 2008
EXTENSIONS
More terms from Harvey P. Dale, Mar 19 2012
Missing terms added by Colin Barker, Dec 01 2015
STATUS
approved