OFFSET
0,2
FORMULA
a(2n) = a(n-2)+2a(n-1)+2, a(2n+1) = 2a(n-1)+a(n)+2. - Ralf Stephan, Oct 08 2003
PROG
(PARI) a(n)=if(n<2, if(n<1, 1, 3), if(n%2==0, if(n==2, 4, a(n/2-2)+2*a(n/2-1)+2), 2*a((n-3)/2)+a((n-1)/2)+2))
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, May 24 2002
STATUS
approved