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 A034810 #14 Aug 13 2024 22:54:00
%S A034810 7,10,13,16,19,36,37,40,43,46,58,63,74,85,88,97,98,104,125,132,143,
%T A034810 153,156,164,168,169,175,188,196,203,206,222,224,233,241,269,292,304,
%U A034810 305,308,311,317,331,333,338,344,359,364,367,368,372,382,389,395,397,409
%N A034810 Concatenation of 'prevprime(k) and k and nextprime(k)' is a prime.
%H A034810 Andrew Howroyd, <a href="/A034810/b034810.txt">Table of n, a(n) for n = 1..10000</a>
%e A034810 n=88 --> previous prime is 83, next prime is 89, thus '838889' is a prime.
%t A034810 coQ[n_]:=PrimeQ[FromDigits[Flatten[IntegerDigits[{NextPrime[n,-1],n,NextPrime[n]}]]]]; Select[Range[3,409],coQ[#]&] (* _Jayanta Basu_, May 30 2013 *)
%o A034810 (PARI) isok(n)=n>2 && isprime(fromdigits(concat([digits(precprime(n-1)), digits(n), digits(nextprime(n+1))]))) \\ _Andrew Howroyd_, Aug 13 2024
%Y A034810 Cf. A034808-A034821.
%K A034810 nonn,base
%O A034810 1,1
%A A034810 _Patrick De Geest_, Oct 15 1998
%E A034810 Offset changed by _Andrew Howroyd_, Aug 13 2024