A102727 - OEIS

%I #10 Sep 08 2022 08:45:16

%S 6,7,10,13,25,36,43,54,73,75,96,99,103,105,108,112,115,150,157,171,

%T 189,208,223,228,237,262,264,292,300,312,328,340,349,351,361,372,379,

%U 388,391,409,421,424,435,444,459,465,466,481,484,501,504,508,510,535,552,565,579,580,586,610,612,619

%N Numbers k such that k1111111 is prime.

%e If k=6, then k1111111 = 61111111 (prime).

%e If k=54, then k1111111 = 541111111 (prime).

%e If k=108, then k1111111 = 1081111111 (prime).

%o (Magma) [ n: n in [1..700] | IsPrime(Seqint([1,1,1,1,1,1,1] cat Intseq(n))) ]; // _Vincenzo Librandi_, Feb 04 2011

%K base,nonn

%O 1,1

%A _Parthasarathy Nambi_, Feb 25 2005