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 A038532 #12 Jun 30 2021 08:35:35
%S A038532 97,1213,2137,2861,3067,3271,3373,3583,48131,55163,56167,57173,62191,
%T A038532 70229,86293,90313,93337,96353,99367,104383,105389,106397,108401,
%U A038532 117443,123479,126499,129509,132523,133541,138569,143593,145601
%N A038532 Primes that are concatenations of k-th composite and k-th prime.
%H A038532 Harvey P. Dale, <a href="/A038532/b038532.txt">Table of n, a(n) for n = 1..1000</a>
%t A038532 nn=250;Module[{prs=Prime[Range[nn]],comps,concats},comps=Take[Complement[ Range[2,Prime[nn]+1], prs],nn];concats=FromDigits[Flatten[ IntegerDigits/@#]]&/@ Thread[{comps,prs}];Select[concats,PrimeQ]] (* _Harvey P. Dale_, Apr 27 2012 *)
%Y A038532 Cf. A038531.
%K A038532 nonn,base
%O A038532 1,1
%A A038532 Vasiliy Danilov (danilovv(AT)usa.net), Jul 14 1998
%E A038532 Edited by _Charles R Greathouse IV_, Apr 23 2010