A143222 - OEIS

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

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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] (* Ray Chandler, Nov 09 2008 *)

CROSSREFS

Cf. A143220, A143221.

Sequence in context: A387348 A286493 A189084 * A286490 A372728 A217831

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