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 A034595 #11 Aug 13 2024 22:54:11
%S A034595 27,51,63,123,199,217,219,233,257,341,353,357,417,423,429,473,501,519,
%T A034595 523,551,579,597,609,653,657,667,669,687,703,717,777,783,801,873,891,
%U A034595 971,987,1017,1043,1139,1157,1161,1271,1337,1343,1389,1671,1973,2019
%N A034595 Concatenation of 'nextprime(a(n)) and a(n)' and 'a(n) and nextprime(a(n))' are both prime.
%H A034595 Harvey P. Dale, <a href="/A034595/b034595.txt">Table of n, a(n) for n = 1..1000</a>
%e A034595 a(n)=353 -> nextprime(a(n)) is 359 so '353359' and '359353' are both prime.
%t A034595 bpQ[n_]:=Module[{np=NextPrime[n]},AllTrue[{n*10^IntegerLength[np]+ np, np* 10^IntegerLength[ n]+n}, PrimeQ]]; Select[Range[2100],bpQ] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, May 19 2016 *)
%Y A034595 Intersection of A034591 and A034594.
%Y A034595 Cf. A034596, A034808, A034809, A034814.
%K A034595 nonn,base
%O A034595 1,1
%A A034595 _Patrick De Geest_, Oct 15 1998
%E A034595 Offset changed by _Andrew Howroyd_, Aug 13 2024