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Search: id:A075311
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| A075311 |
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a(1) = 1; for n > 1, a(n) = smallest number m > a(n-1) such that number of 1's in binary expansion of m is not already in the sequence. |
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+0
2
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| 1, 3, 5, 6, 9, 10, 12, 15, 17, 18, 20, 23, 24, 27, 29, 30, 33, 34, 36, 39, 40, 43, 45, 46, 48, 51, 53, 54, 57, 58, 60, 65, 66, 68, 71, 72, 75, 77, 78, 80, 83, 85, 86, 89, 90, 92, 96, 99, 101, 102, 105, 106, 108, 113, 114, 116, 120, 127, 129, 130, 132, 135, 136, 139, 141
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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If A000120(k) is in sequence then k is not.
Differs from A001969: 63 is not included since it has 6 bits set.
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LINKS
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Phil Carmody, Re: New sieve and a challenge
Jon Perry, New sieve and a challenge
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EXAMPLE
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We start with a(1)=1. Then 2 is not included since it has one bit set and 1 is in sequence. Next, 3 is included since it has 2 one bits and 2 is not in sequence. And so on.
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PROGRAM
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(PARI) v=vector(1000): v[1]=1: for(curr=2, 1000, e=A000120(curr): if(v[e], continue, v[curr]=1)): for(k=1, 1000, if(v[k], print1(k", ")))
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CROSSREFS
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Sequence in context: A165740 A080307 A001969 this_sequence A032786 A080309 A018900
Adjacent sequences: A075308 A075309 A075310 this_sequence A075312 A075313 A075314
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KEYWORD
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easy,nonn
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AUTHOR
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Phil Carmody (pc+oeis(AT)asdf.org), Oct 11 2002
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EXTENSIONS
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Edited by Ralf Stephan (ralf(AT)ark.in-berlin.de), Sep 14 2003
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