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 A074395 #7 Mar 17 2015 23:13:16
%S A074395 6,1,0,5,1,4,0,5,3,0,3,4,0,5,3,2,1,2,5,1,2,5,3,4,4,0,5,1,4,2,5,3,0,3,
%T A074395 0,3,2,5,3,2,1,2,1,4,0,5,5,5,1,4,2,1,2,3,2,3,0,3,4,0,3,2,5,1,4,2,3,2,
%U A074395 1,4,2,5,3,2,5,3,4,4,4,2,1,2,1,2,5,3,4,4,0,5,5,5,5,5,5,3,4,0,3,2,3,2,3,0,3
%N A074395 A 7-way classification of the primes.
%C A074395 There are seven types of consecutive primes modulus 4 and whether or not they are twin primes. They are a (1, 3, paired), (3, 1, paired), (1, 3, not paired), (3, 1, not paired), (1, 1), (3, 3) and p(m)=2. Each case is mapped to a number from zero to six, respectively. Here the word paired means that the consecutive primes are twins.
%C A074395 The initial digit (6) occurs but once and the frequency for the digits 0 and 1 decreased with added terms.
%t A074395 a = {}; Do[p = Prime[n]; q = Prime[n + 1]; a = Append[a, Which[ Mod[p, 4] == 1 && Mod[q, 4] == 3 && p + 2 == q, 0, Mod[p, 4] == 3 && Mod[q, 4] == 1 && p + 2 == q, 1, Mod[p, 4] == 1 && Mod[q, 4] == 3 && p + 2 != q, 2, Mod[p, 4] == 3 && Mod[q, 4] == 1 && p + 2 != q, 3, Mod[p, 4] == 1 && Mod[q, 4] == 1, 4, Mod[p, 4] == 3 && Mod[q, 4] == 3, 5, p == 2, 6]]; p = q, {n, 1, 105}]; a
%Y A074395 Cf. A071696, A071698.
%K A074395 nonn
%O A074395 1,1
%A A074395 _Roger L. Bagula_, Sep 24 2002
%E A074395 Edited and extended by _Robert G. Wilson v_, Oct 03 2002