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%I #10 May 25 2018 08:27:16
%S 1,2,4,8,11,12,18,21,31,34,46,47,50,61,78,84,85,90,99,100,101,106,110,
%T 111,114,131,133,138,141,157,159,167,169,172,175,183,197,198,211,229,
%U 231,232,233,235,260,261,269,276,285,289,295,306,322,337,339,340,347
%N Values of n corresponding to the primes given in A073640. The concatenation of the a(n) and a(n+1)th primes for any n is also prime.
%F A073640(n) = prime(a(n)), with a(n) the n-th term in this sequence.
%e E.g. For n=5: a(5)=11, a(6)=12 and the concatenation of 11th and 12th primes is 3137, which is also prime. The 5th and 6th terms in A073640 are 31 and 37.
%p nout := [1]: for n from 2 to 1000 do: p := ithprime(n): d := parse(cat(pout[nops(pout)],p)): if (isprime(d)) then nout := [op(nout),n]: fi: od:
%Y Cf. A073640.
%K nonn,base
%O 1,2
%A Mark Hudson (mrmarkhudson(AT)hotmail.com), Jan 31 2003
%E Edited by _Charles R Greathouse IV_, Apr 26 2010