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 A165292 #10 Apr 03 2023 10:36:11
%S A165292 37,311,313,317,331,337,347,353,359,367,373,379,383,389,397,3109,3137,
%T A165292 3163,3167,3181,3191,3229,3251,3257,3271,3307,3313,3331,3347,3359,
%U A165292 3373,3389,3433,3449,3457,3461,3463,3467,3491,3499,3541,3547,3557,3571,3593
%N A165292 Primes obtained from other primes by pre-concatenating with 3.
%C A165292 The primes are considered in increasing order. These primes are obtained by adding 30, 300, 3000, ... to other primes.
%H A165292 Chris Caldwell, <a href="https://t5k.org/lists/small/10000.txt">The First 10,000 Primes</a>
%e A165292 The prime 3389 is obtained from the prime 389 by pre-concatenating with 3.
%t A165292 Select[(FromDigits[Join[{3},IntegerDigits[#]]]&/@Prime[Range[200]]),PrimeQ] (* _Harvey P. Dale_, Mar 04 2011 *)
%Y A165292 Cf. A000040, A165243
%K A165292 base,nonn
%O A165292 1,1
%A A165292 _Parthasarathy Nambi_, Sep 13 2009
%E A165292 359 inserted by _R. J. Mathar_, Sep 21 2009