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 A321363 #27 Dec 09 2024 15:45:45
%S A321363 3,5,7,13,17,19,31,37,53,59,71,73,79,97,113,331,337,557,773,991,997,
%T A321363 1117,3331,5557,11113,11117,11119,33331,77773,99991,111119,333331,
%U A321363 333337,555557,3333331,9999991,11111117,11111119,33333331,55555553,55555559,111111113
%N A321363 Single-digit odd primes and primes whose decimal expansion has the form iii...ij, where i and j are distinct odd digits.
%t A321363 s={3, 5, 7}; Do[Do[Do[k=m*(10^n-1)/9*10+j; If[j!=m && PrimeQ[k], AppendTo[s, k]], {j,1,9,2}], {m,1,9,2}], {n,1,8}]; s (* _Amiram Eldar_, Nov 08 2018 *)
%o A321363 (PARI) lista(nn) = {print1("3, 5, 7, "); for (n=1, nn, r = (10^n-1)/9; forstep (i=1, 9, 2, forstep(j=1, 9, 2, if (i != j, if (isprime(p=fromdigits(concat(digits(r*i), j))), print1(p, ", "));););););} \\ _Michel Marcus_, Nov 28 2018
%Y A321363 Subsequence of A030096.
%Y A321363 Cf. A051200, A055558, A062353, A065582, A105975, A141311, A320256.
%K A321363 nonn,base
%O A321363 1,1
%A A321363 _Enrique Navarrete_, Nov 07 2018
%E A321363 a(35)-a(42) from _Amiram Eldar_, Nov 08 2018