This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A102248 #13 Jul 07 2019 13:19:15
%S A102248 2,4,8,10,16,22,25,26,28,35,40,44,47,50,58,65,68,70,79,80,86,92,94,95,
%T A102248 101,109,112,113,128,131,136,140,142,143,149,152,154,169,170,179,182,
%U A102248 184,187,196,205,208,217,218,227,235,236,260,262,263,266,278,283,284
%N A102248 Numbers n such that n111 is prime.
%H A102248 Harvey P. Dale, <a href="/A102248/b102248.txt">Table of n, a(n) for n = 1..1000</a>
%e A102248 At n=2, n111 = 2111 (prime).
%e A102248 At n=50, n111 = 50111 (prime).
%e A102248 At n=95, n111 = 95111 (prime).
%t A102248 Select[ Range[ 290], PrimeQ[ FromDigits[ Flatten[ IntegerDigits /@ { #, 1, 1, 1}]]] &] (* _Robert G. Wilson v_, Feb 21 2005 *)
%t A102248 Select[Range[300],PrimeQ[1000#+111]&] (* _Harvey P. Dale_, Jul 07 2019 *)
%o A102248 (PARI) is(n)=isprime(1000*n+111) \\ _Charles R Greathouse IV_, May 22 2017
%Y A102248 Cf. A024912.
%K A102248 nonn,base
%O A102248 1,1
%A A102248 _Parthasarathy Nambi_, Feb 18 2005
%E A102248 More terms from _Robert G. Wilson v_, Feb 21 2005