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 A262578 #36 Nov 17 2024 07:16:29
%S A262578 1,12,123,1234,12345,123456,1234567,12345679,1234567910,123456791011,
%T A262578 12345679101112,1234567910111213,123456791011121314,
%U A262578 12345679101112131415,1234567910111213141516,123456791011121314151617,12345679101112131415161718,1234567910111213141516171819,123456791011121314151617181920
%N A262578 Concatenation of the numbers from 1 to n but omitting 8.
%C A262578 The first (probable) prime in this sequence is a(1872) = 1234567910111213...1873 (ending at 1873), a 6384-digit probable prime, too large to display here. It was found by _David Broadhurst_ on Sep 27 2015.
%C A262578 No other primes through a(10000). - _Robert Price_, Nov 04 2018
%C A262578 a(1872) is prime. - _Jason Yuen_, Nov 17 2024
%t A262578 Module[{nn=30, c}, c=Drop[Range[nn], {8}]; Table[FromDigits[Flatten[IntegerDigits/@Take[c, n]]], {n, nn-1}]] (* _Vincenzo Librandi_, Nov 05 2018 *)
%Y A262578 Cf. A007908, A262299, A262300, A262571-A262582.
%Y A262578 See A262300 for more about this problem.
%K A262578 nonn,base
%O A262578 1,2
%A A262578 _N. J. A. Sloane_, Sep 25 2015