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Primes that are concatenations of n with n + 8.
1

%I #15 Sep 07 2019 09:00:04

%S 19,311,1321,1523,2129,3947,4957,5563,6977,7583,9199,111119,115123,

%T 159167,163171,165173,169177,171179,183191,193201,195203,199207,

%U 201209,205213,211219,229237,235243,241249,249257,265273

%N Primes that are concatenations of n with n + 8.

%H Harvey P. Dale, <a href="/A032631/b032631.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[Table[FromDigits[Flatten[IntegerDigits/@{n,n+8}]],{n,1,301,2}], PrimeQ](* _Harvey P. Dale_, Sep 07 2019 *)

%Y Cf. A032613, A032623.

%K nonn,base

%O 1,1

%A _Patrick De Geest_, May 15 1998

%E Edited by _Charles R Greathouse IV_, Apr 28 2010