%I #12 Sep 08 2022 08:45:53

%S 53,503,5003,500000003,5000000000000000003,500000000000000000003,

%T 50000000000000000000000000000003,

%U 5000000000000000000000000000000000000000003

%N Primes of the form (5*10^n+3).

%H Vincenzo Librandi, <a href="/A177120/b177120.txt">Table of n, a(n) for n = 1..13</a>

%H Makoto Kamada, <a href="https://stdkmd.net/nrr/5/50003.htm#prime">Prime numbers of the form 500...003</a>.

%t Select[5 10^Range[80] + 3, PrimeQ] (* _Vincenzo Librandi_, May 11 2013 *)

%o (Magma)[ a: n in [0..250]|IsPrime(a) where a is 5*10^n+3]

%Y Cf. A096254.

%K nonn

%O 1,1

%A _Vincenzo Librandi_, Dec 10 2010