OFFSET
0,2
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 0..10000
EXAMPLE
a(20) = #{0,1,2,4,5,7,8,9,10,14,15,16,17,18,20} = #{0,1,10,100,101,111,1000,1001,1010,1110,1111,10000,10001,10010,10100} = 15.
MATHEMATICA
Accumulate[Table[If[Count[Split[IntegerDigits[n, 2]], {1, 1}]>0, 0, 1], {n, 0, 80}]] (* Harvey P. Dale, Feb 12 2017 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Reinhard Zumkeller, Feb 07 2010
STATUS
approved