OFFSET
0,6
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (0,1,0,2).
FORMULA
a(4*n) + a(4*n+1) = a(4*n+2).
a(n) + a(n+2) = 2^floor(n/2) = A016116(n).
O.g.f.: x - x^2*(1 + 2*x^3)/((2*x^2-1)*(x^2+1)) . - R. J. Mathar, Feb 23 2008
PROG
(PARI) a(n)=([0, 1, 0, 0; 0, 0, 1, 0; 0, 0, 0, 1; 2, 0, 1, 0]^n*[0; 1; 1; 0])[1, 1] \\ Charles R Greathouse IV, Oct 03 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paul Curtz, Jan 04 2008
EXTENSIONS
Terms a(24) and beyond from Andrew Howroyd, Feb 02 2020
STATUS
approved