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A143221
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a(0)=1. 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.
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2
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1, 0, 0, 1, 0, 1, 1, 1, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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EXAMPLE
| The binary representation of 21 is 10101. This occurs in the concatenation of terms a(0) through a(20) like so: 10010111(10101)00010010. So a(21) = 0.
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MATHEMATICA
| f[l_List]:=Append[l, Boole[StringPosition[ToString[FromDigits[l]], ToString[FromDigits[IntegerDigits[Length[l], 2]]]]=={}]]; Nest[f, {1}, 125] [From Ray Chandler (rayjchandler(AT)sbcglobal.net), Nov 09 2008]
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CROSSREFS
| Cf. A143220, A143222.
Sequence in context: A011749 A188578 A104105 * A126999 A120527 A071004
Adjacent sequences: A143218 A143219 A143220 * A143222 A143223 A143224
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KEYWORD
| base,nonn
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AUTHOR
| Leroy Quet, Jul 30 2008
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EXTENSIONS
| Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Nov 09 2008
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