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A154520
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The prime(n)-th digit of the concatenated non-primes.
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2
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1, 4, 8, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 5, 5, 5, 5, 6, 6, 7, 7, 7, 7, 7, 8, 9, 9, 9, 9, 0, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 3, 1, 3, 4, 1, 4, 4, 4, 5, 1, 1, 5, 1, 6, 1, 6, 1, 7, 1, 1, 8, 1, 8, 8, 1, 1, 1, 0, 0, 2, 0, 2, 1, 2, 1, 2, 2, 2, 2, 2, 3, 2, 3, 3, 2, 4, 2, 4, 4, 5, 2, 2, 2, 6, 7, 7, 2
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| The concatenated non-primes A141468 are A129808 with an initial 0.
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FORMULA
| a(n) = A129808(prime(n)-1) .
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MAPLE
| a129808 := [1] : for n from 4 to 400 do if not isprime(n) then a129808 := [op(a129808), op(ListTools[Reverse](convert(n, base, 10))) ] ; fi; od:
for n from 1 do p := ithprime(n) ; printf("%d, ", op(p-1, a129808) ) ; od: # R. J. Mathar, Aug 03 2009
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CROSSREFS
| Cf. A000040, A141468.
Sequence in context: A021875 A200356 A127734 * A002390 A193087 A201404
Adjacent sequences: A154517 A154518 A154519 * A154521 A154522 A154523
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KEYWORD
| nonn,base
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AUTHOR
| Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Jan 11 2009
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EXTENSIONS
| Edited and extended by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 03 2009
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