A180949 - OEIS

%I #5 Mar 31 2012 13:22:06

%S 223283,248903,924773,1469627,2121767,2428241,2429411,2614043,2885453,

%T 3444893,3512849,3564461,4316141,4438067,4605977,4980161,5267519,

%U 6248057,6961673,7519607,8517563,9716789,9846443,12383099,13127507

%N Prime numbers P such that 10^(n+d+1) + P*10^n + 1 is prime for n=1 to 5 with d = number of digits of P.

%C For P = 6961673,9846443,17990729,28587371 Q is prime for n=1 to 6

%C For P = 5267519,27060587 Q is prime for n=1 to 7

%e 5267519

%e 1052675191

%e 10526751901

%e 105267519001

%e 1052675190001

%e 10526751900001

%e 105267519000001

%e 1052675190000001

%e are all prime numbers

%K nonn,base

%O 1,1

%A _Pierre CAMI_, Sep 27 2010