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 A268858 #39 Sep 08 2022 08:46:15
%S A268858 139,239,439,739,839,1039,1439,2039,2239,2339,2539,2939,3539,3739,
%T A268858 4139,4339,4639,5039,5639,5839,5939,7039,7639,8039,8539,8839,9239,
%U A268858 9439,9539,9739,9839,10039,10139,10639,10739,10939,11239,11839,11939,12239,12539,12739
%N A268858 Prime numbers ending in 39.
%H A268858 Soumil Mandal, <a href="/A268858/b268858.txt">Table of n, a(n) for n = 1..1000</a>
%p A268858 A268858:=n->`if`(isprime(n) and n mod 100 = 39, n, NULL): seq(A268858(n), n=1..4*10^4); # _Wesley Ivan Hurt_, Apr 02 2016
%t A268858 Select[Table[39 + 100 i, {i, 0, 10^3}], ProvablePrimeQ[#] &]
%o A268858 (Magma) [n: n in PrimesUpTo(15000) | n mod 100 eq 39]; // _Vincenzo Librandi_, Feb 15 2016
%o A268858 (PARI) lista(nn) = {for(n=1, nn, if (isprime(p=100*n+39), print1(p, ", ")););} \\ _Michel Marcus_, Feb 20 2016
%o A268858 (Python)
%o A268858 from sympy import isprime
%o A268858 for n in range(139,15000,100):
%o A268858 if(isprime(n)):print(n)
%o A268858 # _Soumil Mandal_, Apr 03 2016
%Y A268858 Cf. A268859, A268860.
%K A268858 nonn,base
%O A268858 1,1
%A A268858 _Soumadeep Ghosh_, Feb 14 2016