OFFSET
1,1
FORMULA
For n>=2, a(n)=2^k+2, if 2^k<=n<=2^k+2^(k-1)-1; a(n)=2^k+2j+3, if n=2^k+2^(k-1)+j, 0<=j<=2^(k-1)-1.
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Shevelev, Apr 17 2009
STATUS
approved