%I A098428
%S A098428 0,0,0,0,1,1,2,2,2,2,3,3,4,4,4,4,5,5,5,5,5,5,6,6,6,6,6,6,6,6,7,7,7,7,7,
%T A098428 7,8,8,8,8,9,9,9,9,9,9,10,10,10,10,10,10,11,11,11,11,11,11,11,11,12,12,
%U A098428 12,12,12,12,13,13,13,13,13,13,14,14,14,14,14,14,14,14,14,14,15,15,15
%N A098428 Number of sexy prime pairs (p, p+6) with p <= n.
%C A098428 Convention: a prime pair is <= n iff its smallest member is <= n.
%C A098428 Since there are 2 congruence classes of sexy prime pairs, (-1, -1) (mod 
               6) and (+1, +1) (mod 6), the number of sexy prime pairs up to n is 
               the sum of the number of sexy prime pairs for each class, expected 
               to be asymptotically the same for both (with the expected Chebyshev 
               bias against the quadratic residue class (+1, +1) (mod 6), which 
               doesn't affect the asymptotic distribution among the 2 classes.) 
               [From Daniel Forgues (squid(AT)zenearch.com), Aug 05 2009]
%H A098428 Daniel Forgues, <a href="b098428.txt">Table of n, a(n) for n=1..99994</
               a>
%H A098428 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               SexyPrimes.html">Sexy Primes</a>
%e A098428 First sexy prime pairs: (5,11),(7,13),(11,17),(13,19), ...
%e A098428 therefore the sequence starts: 0 0 0 0 1 1 2 2 2 2 3 3 4 ...
%Y A098428 Cf. A023201, A046117, A098424, A071538, A098429.
%Y A098428 Sequence in context: A048273 A024542 A098424 this_sequence A023193 A096605 
               A109497
%Y A098428 Adjacent sequences: A098425 A098426 A098427 this_sequence A098429 A098430 
               A098431
%K A098428 nonn
%O A098428 1,7
%A A098428 Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Sep 07 2004
%E A098428 Commented and edited by Daniel Forgues (squid(AT)zensearch.com), Aug 
               01 2009