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 A178378 #3 Mar 30 2012 18:52:41 %S A178378 4,6,9,10,15,22,25,33,34,51,55,58,82,85,87,118,121,123,142,145,177, %T A178378 187,202,205,213,214,274,289,295,298,303,319,321,355,358,382,394,411, %U A178378 447,451,454,478,493,505,535,537,538,562,573,591,622,649,681,685,694,697 %N A178378 Products of 2 primes that are the difference of 2 primes. %F A178378 a(n)=A124588(m)*A124588(k). %e A178378 a(1)=4 because 4=2*2=(5-3)*(5-3) where 2,3,5 and 5-3 are all prime, a(2)=6 because 6=2*3=(5-3)*(5-2) where 2,3,5,5-3 and 5-2 are all prime. %Y A178378 Cf. A000040, A001358. %K A178378 nonn %O A178378 1,1 %A A178378 _Juri-Stepan Gerasimov_, May 26 2010 %E A178378 Extended beyond 478 by _R. J. Mathar_, May 28 2010