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 A273919 #12 Jun 09 2016 04:34:47
%S A273919 0,0,0,3,57,984,22551
%N A273919 Number of 9-tuples of primes in arithmetic progression less than 10^n.
%D A273919 See A113827.
%e A273919 The least 9-tuple is {199, 409, 619, 829, 1039, 1249, 1459, 1669, 1879}, which is also the beginning of the least 10-tuple. This explains a(n)=0 for n<4.
%Y A273919 Cf. A113827 (prime beginning minimal n-tuple of primes in AP).
%Y A273919 Cf. A005115, A115608, A115609, A115610, A115611, A115612, A115613, A273920, A273921, A273922, A273923.
%K A273919 nonn,hard,more
%O A273919 1,4
%A A273919 _Jean-Marc Rebert_, Jun 04 2016