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A154520 The prime(n)-th digit of the concatenated nonprimes. 2
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; text; internal format)
OFFSET

1,2

COMMENTS

The concatenated nonprimes A141468 are A129808 with an initial 0.

LINKS

Table of n, a(n) for n=1..105.

FORMULA

a(n) = A129808(prime(n)-1) .

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

CROSSREFS

Cf. A000040, A141468.

Sequence in context: A021875 A200356 A127734 * A244690 A002390 A193087

Adjacent sequences:  A154517 A154518 A154519 * A154521 A154522 A154523

KEYWORD

nonn,base

AUTHOR

Juri-Stepan Gerasimov, Jan 11 2009

EXTENSIONS

Edited and extended by R. J. Mathar, Aug 03 2009

STATUS

approved

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Last modified December 15 20:00 EST 2019. Contains 330000 sequences. (Running on oeis4.)