OFFSET
0,1
COMMENTS
a(n+2) is the Hankel transform of A110199. - Paul Barry, Jun 23 2010
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,1,0,-1).
FORMULA
G.f.: (1+x)/(1-x^2+x^4).
a(n) = a(n-2)-a(n-4). - Wesley Ivan Hurt, May 09 2021
MATHEMATICA
LinearRecurrence[{0, 1, 0, -1}, {1, 1, 1, 1}, 50] (* G. C. Greubel, May 14 2016 *)
PROG
(Magma) &cat [[1, 1, 1, 1, 0, 0, -1, -1, -1, -1, 0, 0]^^10]; // Vincenzo Librandi, May 15 2016
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Paul Barry, Oct 13 2009
EXTENSIONS
Incorrect comment removed - R. J. Mathar, Oct 02 2012
STATUS
approved