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Search: id:A087381
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| A087381 |
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Let Compri(n) be the number obtained by replacing each prime digit (2,3,5,7) of n by a '1' and a composite digit( 0,4,6,8,9) by a '0' . A 1 remains the same. a(n) = Compri(n). |
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+0
2
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| 1, 1, 1, 0, 1, 0, 1, 0, 0, 10, 11, 11, 11, 10, 11, 10, 11, 10, 10, 10, 11, 11, 11, 10, 11, 10, 11, 10, 10, 10, 11, 11, 11, 10, 11, 10, 11, 10, 10, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 10, 11, 11, 11, 10, 11, 10, 11, 10, 10, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 10, 11, 11, 11, 10, 11, 10, 11, 10, 10, 0
(list; graph; listen)
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OFFSET
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1,10
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COMMENT
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For all numbers using only composite digits( 0,4,6,8,9,) a(n) = 0. For a 'k' digit number using 1 and/or only prime digits a(n) = (10^k-1)/9.
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EXAMPLE
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a(4206) = 100
a(10235479) = 10111010
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CROSSREFS
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Cf. A087380.
Sequence in context: A077812 A004288 A065016 this_sequence A136400 A121266 A045988
Adjacent sequences: A087378 A087379 A087380 this_sequence A087382 A087383 A087384
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KEYWORD
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base,nonn
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Sep 09 2003
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EXTENSIONS
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More terms from David Wasserman (wasserma(AT)spawar.navy.mil), May 25 2005
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