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 A120823 #15 Apr 08 2025 22:06:47
%S A120823 1,29,269,689
%N A120823 a(n) consecutive digits ascending beginning with the digit 5 give a prime..
%C A120823 Digits are in ascending order beginning with 5 and after 9 comes 0.
%C A120823 The sequence "a(n) consecutive digits descending beginning with the digit 5 give a prime." has only one term, 1 which represents the prime 5.
%C A120823 a(5) > 10^5. - _Michael S. Branicky_, Apr 08 2025
%e A120823 29 is a term since the 29-digit number 56789012345678901234567890123 is a prime.
%t A120823 fQ[n_] := PrimeQ@ FromDigits@ Mod[4+Range@n, 10]; lst = {}; Do[ If[fQ@n, AppendTo[lst, n]; Print@n], {n, 9000}]; lst
%Y A120823 Cf. A006055, A120819, A120820, A120821, A120822, A120824, A120825, A120826, A120827.
%K A120823 nonn,base,hard,more
%O A120823 1,2
%A A120823 _Robert G. Wilson v_, Jul 05 2006