OFFSET
0,3
COMMENTS
Apart from initial terms and offset, same as A160573, but has a slightly nice recurrence.
FORMULA
a(0) = 0, a(2^k) = k+1; for n >= 3, if n = 2^i + j, 1 <= j < 2^i, a(n) = a(j) + a(j+1).
MAPLE
G:= x + x^2 * mul( 1 + x^(2^n-1) + x^(2^n), n=0..20);
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jun 03 2009
STATUS
approved