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 A242833 #16 Oct 22 2014 03:54:38
%S A242833 5,52631,5263157894736842105263157,
%T A242833 52631578947368421052631578947368421052631578947368421052631
%N A242833 Primes formed by the initial digits of the decimal expansion of 1/19, starting at the first nonzero digit in the expansion.
%C A242833 a(5) has 95 digits and a(6) has 907 digits. - _Michel Marcus_, May 27 2014
%H A242833 Jon E. Schoenfield, <a href="/A242833/b242833.txt">Table of n, a(n) for n = 1..6</a>
%o A242833 (PARI) lista(nn) = {v = [5,2,6,3,1,5,7,8,9,4,7,3,6,8,4,2,1,0]; n = 0; for (i=0, nn, n = 10*n+ v[(i % 18)+1]; if (ispseudoprime(n), print1(n, ", ")););} \\ _Michel Marcus_, May 27 2014
%Y A242833 Cf. A021023.
%Y A242833 Corresponding sequences for 1/k: A242824 (k=7), A093676 (k=12), A242826 (k=13), A242827(k=14), A242828 (k=17).
%K A242833 base,nonn
%O A242833 1,1
%A A242833 _Felix Fröhlich_, May 23 2014