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A229123
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a(n) gives the number of bases, b>1, in which n is an early bird.
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1
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0, 0, 1, 0, 2, 2, 3, 2, 3, 2, 4, 3, 6, 4, 5, 3, 7, 2, 7, 5, 7, 6, 7, 4, 9, 7, 6, 5, 8, 5, 10, 4, 8, 8, 7, 5, 13, 8, 8, 6, 12, 7, 12, 7, 8, 11, 11, 5, 13, 9, 12, 9, 11, 5, 13, 11, 13, 12, 12, 5, 17, 11, 11, 8, 13, 9, 14, 9, 12, 7, 14, 8, 18, 11, 9, 11, 13, 11
(list;
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refs;
listen;
history;
text;
internal format)
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OFFSET
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1,5
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COMMENTS
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A number n is called an early bird in base b, if its digits in base b appear in the concatenation of the digits in base b of the numbers from 1 to n-1.
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LINKS
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Paul Tek, Table of n, a(n) for n = 1..10000
Paul Tek, C program for this sequence
Paul Tek, Illustration of the bases in which n is an early bird, where n ranges from 1 to 1000
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EXAMPLE
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The number 1 is never an early bird, so a(1)=0.
The number 3 is an early bird only in base 2, so a(3)=1.
The number 7 is an early bird in bases 2, 3 and 5, so a(7)=3.
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PROG
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(C) See Link section.
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CROSSREFS
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Cf. A116700, A161373, A135549.
Sequence in context: A327161 A350067 A308450 * A173908 A329045 A329345
Adjacent sequences: A229120 A229121 A229122 * A229124 A229125 A229126
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KEYWORD
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nonn,base
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AUTHOR
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Paul Tek, Sep 14 2013
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STATUS
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approved
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