A154520 The prime(n)-th digit of the concatenated nonprimes.

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

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