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 A290407 #17 Sep 08 2022 08:46:19
%S A290407 83,811,823,829,853,859,883,8101,8167,8179,8191,8233,8263,8269,8293,
%T A290407 8311,8317,8353,8389,8419,8431,8443,8461,8467,8521,8563,8599,8641,
%U A290407 8647,8677,8719,8761,8821,8839,8863,8887,8929,8941,8971,81013,81019,81031,81049,81097
%N A290407 Primes obtained from other primes by prefixing an 8.
%C A290407 Except a(1), all the terms in this sequence are congruent to 1 mod 3.
%H A290407 Robert Israel, <a href="/A290407/b290407.txt">Table of n, a(n) for n = 1..10000</a>
%e A290407 823 is in the sequence because it is a prime obtained by prefixing an 8 to the prime 23.
%e A290407 8317 is in the sequence because it is a prime obtained by prefixing an 8 to the prime 317.
%p A290407 A290407:= n-> (parse(cat(8, ithprime(n)))): select(isprime, [seq((A290407 (n), n=1..1000))]);
%t A290407 Select[k = 8; Table[FromDigits[Join[IntegerDigits[k], IntegerDigits[Prime[n]]]], {n, 500}], PrimeQ]
%o A290407 (PARI) forprime(p = 2,5000, k=eval(concat(8,Str(p))); if(isprime(k), print1(k,", ")));
%o A290407 (Magma) [k : p in PrimesUpTo (5000) | IsPrime (k) where k is Seqint (Intseq (p) cat Intseq (8))];
%Y A290407 Subsequence of A045714.
%Y A290407 Cf. A165555, A167187, A289866, A289867.
%K A290407 nonn,base
%O A290407 1,1
%A A290407 _K. D. Bajpai_, Jul 30 2017