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 A163858 #3 Mar 31 2012 14:01:22 %S A163858 0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,3,3,3,3, %T A163858 3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,5,5, %U A163858 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,6,6,6,6,7,7,7,7,7 %N A163858 Number of sexy prime triples (p, p+6, p+12) where p+18 is not prime (although p-6 might be), with p <= n. %C A163858 p-6 will be prime if the prime triple contains the last 3 primes of a sexy prime quadruple. %C A163858 There are two sexy prime triples classes, (-1, -1, -1) (mod 6) and (+1, +1, +1) (mod 6). They should asymptotically have the same number of triples, if there is an infinity of such triples, although with a Chebyshev bias expected against the quadratic residue class triples (+1, +1, +1) (mod 6), which doesn't affect the asymptotic result. This sequence counts both classes. %C A163858 Also the sexy prime triples of class (-1, -1, -1) (mod 6) fall within (11, 17, 23, 29) (mod 30) while the sexy prime triples of class (+1, +1, +1) (mod 6) fall within (1, 7, 13, 19) (mod 30). %H A163858 Daniel Forgues, <a href="/A163858/b163858.txt">Table of n, a(n) for n=1..99982</a> %Y A163858 A046118 Smallest member of a sexy prime triple: value of p where (p, p+6, p+12) are all prime but p+18 is not (although p-6 might be.) %Y A163858 A046119 Middle member of a sexy prime triple: value of p+6 where (p, p+6, p+12) are all prime but p+18 is not (although p-6 might be.) %Y A163858 A046120 Largest member of a sexy prime triple, value of p+12 where (p, p+6, p+12) are all prime but p+18 is not (although p-6 might be.) %K A163858 nonn %O A163858 1,17 %A A163858 _Daniel Forgues_, Aug 05 2009, Aug 12 2009