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 A120827 #9 Apr 22 2025 18:21:31
%S A120827 13,29,43
%N A120827 a(n) consecutive digits ascending beginning with the digit 9 give a prime.
%C A120827 Digits are in ascending order beginning with 9 and after 9 comes 0.
%C A120827 The sequence "a(n) consecutive digits descending beginning with the digit 9 give a prime" has no terms.
%C A120827 There is no further term up to 26000. - _Farideh Firoozbakht_, Sep 11 2006
%C A120827 There is no further term up to 150000. - _Michael S. Branicky_, Apr 22 2025
%e A120827 13 is a term since 9012345678901 is a prime.
%t A120827 fQ[n_] := PrimeQ@ FromDigits@ Mod[8+Range@n, 10]; lst = {}; Do[ If[fQ@n, AppendTo[lst, n]; Print@n], {n, 5000}]; lst
%t A120827 Flatten[Position[Table[FromDigits[PadRight[{},n,{9,0,1,2,3,4,5,6,7,8}]],{n,100}],_?PrimeQ]] (* _Harvey P. Dale_, Sep 06 2015 *)
%Y A120827 Cf. A006055, A120819, A120820, A120821, A120822, A120823, A120824, A120825, A120826.
%K A120827 nonn,base,hard,bref,more
%O A120827 1,1
%A A120827 _Robert G. Wilson v_, Jul 05 2006