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 A034811 #11 Aug 13 2024 22:53:56
%S A034811 8,23,32,36,44,54,66,74,77,84,91,104,113,115,122,130,132,162,174,178,
%T A034811 187,188,191,204,212,222,224,232,235,259,267,281,286,295,302,305,317,
%U A034811 325,344,353,367,368,384,389,391,401,406,427,430,433,457,458,461,464
%N A034811 Concatenation of 'nextprime(k) and k and prevprime(k)' is a prime.
%H A034811 Harvey P. Dale, <a href="/A034811/b034811.txt">Table of n, a(n) for n = 1..1000</a>
%e A034811 n=353 -> next prime is 359, previous prime is 349, thus '359353349' is a prime.
%t A034811 Select[Range[500],PrimeQ[FromDigits[Flatten[IntegerDigits/@ { NextPrime[#], #, NextPrime[ #,-1]}]]]&] (* _Harvey P. Dale_, Jan 12 2016 *)
%o A034811 (PARI) isok(n)=n>2 && isprime(fromdigits(concat([digits(nextprime(n+1)), digits(n), digits(precprime(n-1))]))) \\ _Andrew Howroyd_, Aug 13 2024
%Y A034811 Cf. A034808-A034821.
%K A034811 nonn,base
%O A034811 1,1
%A A034811 _Patrick De Geest_, Oct 15 1998
%E A034811 Offset changed by _Andrew Howroyd_, Aug 13 2024