A102816 - OEIS

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

%S 14,17,31,35,40,53,58,73,77,94,95,101,109,116,142,149,164,196,218,226,

%T 227,233,236,253,256,257,266,268,281,295,302,311,340,341,355,359,374,

%U 385,415,418,421,428,442,443,466,469,491,542,563,571,583,599,604,614,632,656,665,667,668

%N Numbers k such that k111111111 is prime.

%e If k=14, then k111111111 = 14111111111 (prime).

%e If k=73, then k111111111 = 73111111111 (prime).

%e If k=142, then k111111111 = 142111111111 (prime).

%o (Magma) [ n: n in [1..700] | IsPrime(Seqint([1,1,1,1,1,1,1,1,1] cat Intseq(n))) ]; // _Vincenzo Librandi_, Feb 03 2011

%K base,nonn

%O 1,1

%A _Parthasarathy Nambi_, Feb 26 2005