OFFSET
0,3
FORMULA
Equals 4^n - A019309(n).
a(0)=a(1)=0, a(2n)=4^n + 4a(2n-1) - a(n), a(2n+1)=4a(2n). - Emeric Deutsch, Feb 04 2006
MAPLE
a:=proc(n) if n=0 or n=1 then 0 elif n mod 2 = 0 then 4*a(n-1)-a(n/2)+4^(n/2) else 4*a(n-1) fi end: seq(a(n), n=0..28); # Emeric Deutsch, Feb 04 2006
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jun 06 2004
EXTENSIONS
More terms from Emeric Deutsch, Feb 04 2006
STATUS
approved