OFFSET
0,10
LINKS
Harvey P. Dale, Table of n, a(n) for n = 0..1000
EXAMPLE
9 = 1001 so a(9) = 2.
MATHEMATICA
bd[n_]:=Module[{s=Split[IntegerDigits[n, 2]]}, Which[Length[s]<3, 0, MemberQ[ Last[s], 1], Length[s[[-2]]], True, Length[s[[-3]]]]]; Array[bd, 120, 0] (* Harvey P. Dale, Dec 29 2013 *)
PROG
(PARI) a(n)=local(b, c, s):b=binary(n):c=length(b):while(!b[c], c=c-1):while(c>0&&b[c], c=c-1): if(c<=0, 0, s=0:while(!b[c], c=c-1:s=s+1):s) \\ Ralf Stephan
CROSSREFS
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, Dec 22 2003
EXTENSIONS
More terms from Ralf Stephan, Feb 01 2004
STATUS
approved