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A154520 The prime(n)-th digit of the concatenated nonprimes. 2

%I #6 Jul 16 2015 21:48:45

%S 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,

%T 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,

%U 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

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

%C The concatenated nonprimes A141468 are A129808 with an initial 0.

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

%p 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:

%p for n from 1 do p := ithprime(n) ; printf("%d,", op(p-1,a129808) ) ; od: # _R. J. Mathar_, Aug 03 2009

%Y Cf. A000040, A141468.

%K nonn,base

%O 1,2

%A _Juri-Stepan Gerasimov_, Jan 11 2009

%E Edited and extended by _R. J. Mathar_, Aug 03 2009

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Last modified March 28 04:13 EDT 2024. Contains 371235 sequences. (Running on oeis4.)