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 A240678 #16 Nov 29 2021 11:31:13
%S A240678 11,29,41,47,71,79,83,131,137,139,151,163,173,181,191,227,257,263,277,
%T A240678 281,293,307,311,313,359,383,449,491,503,509,557,563,569,577,587,593,
%U A240678 601,617,647,659,661,677,683,719,739,743,751,809,821,827,857,877,881
%N A240678 Primes p such that p*10+k is prime for exactly one value of the digit k.
%H A240678 Colin Barker, <a href="/A240678/b240678.txt">Table of n, a(n) for n = 1..1000</a>
%e A240678 11 is in the sequence because 113 is prime, but 111, 117 and 119 are not prime.
%t A240678 Select[Prime[Range[200]],Total[Boole[PrimeQ[10 #+{1,3,7,9}]]]==1&] (* _Harvey P. Dale_, Apr 19 2019 *)
%o A240678 (PARI) forprime(p=2, 1500, t=0; forstep(k=1, 9, 2, if(isprime(p*10+k), t++)); if(t==1, print1(p, ", ")))
%o A240678 (Python)
%o A240678 from sympy import isprime, primerange
%o A240678 def ok(p): return sum(1 for k in [1, 3, 7, 9] if isprime(p*10+k)) == 1
%o A240678 def aupto(limit): return [p for p in primerange(1, limit+1) if ok(p)]
%o A240678 print(aupto(881)) # _Michael S. Branicky_, Nov 29 2021
%Y A240678 Cf. A067267, A119289, A240679, A240680, A240689.
%K A240678 nonn,base
%O A240678 1,1
%A A240678 _Colin Barker_, Apr 10 2014