A143222 a(0)=0. For n >=1, a(n) = 0 if the binary representation of n occurs at least once in the concatenation of (a(0),a(1),...,a(n-1)). a(n) = 1 otherwise.

0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1

Offset

0,1

Links

Table of n, a(n) for n=0..104.

Example

The binary representation of 20 is 10100. This occurs in the concatenation of terms a(0) through a(19) like so: 01(10100)1100100111100. So a(20) = 0.

Mathematica

f[l_List]:=Append[l, Boole[StringPosition[ToString[FromDigits[l]], ToString[FromDigits[IntegerDigits[Length[l], 2]]]]=={}]]; Nest[f, {0}, 125] [From Ray Chandler, Nov 09 2008]

Crossrefs

Cf. A143220, A143221.

Sequence in context: A156595 A286493 A189084 * A286490 A217831 A010060

Adjacent sequences: A143219 A143220 A143221 * A143223 A143224 A143225

Keyword

base,nonn

Author

Leroy Quet, Jul 30 2008

Extensions

Extended by Ray Chandler, Nov 09 2008

Status

approved