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 A032631 #15 Sep 07 2019 09:00:04
%S A032631 19,311,1321,1523,2129,3947,4957,5563,6977,7583,9199,111119,115123,
%T A032631 159167,163171,165173,169177,171179,183191,193201,195203,199207,
%U A032631 201209,205213,211219,229237,235243,241249,249257,265273
%N A032631 Primes that are concatenations of n with n + 8.
%H A032631 Harvey P. Dale, <a href="/A032631/b032631.txt">Table of n, a(n) for n = 1..1000</a>
%t A032631 Select[Table[FromDigits[Flatten[IntegerDigits/@{n,n+8}]],{n,1,301,2}], PrimeQ](* _Harvey P. Dale_, Sep 07 2019 *)
%Y A032631 Cf. A032613, A032623.
%K A032631 nonn,base
%O A032631 1,1
%A A032631 _Patrick De Geest_, May 15 1998
%E A032631 Edited by _Charles R Greathouse IV_, Apr 28 2010