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 A215081 #5 Aug 02 2012 17:13:07
%S A215081 2,6,15,10,21,14,55,0,33,22,39,26,85,0,51,34,57,38,115,0,69,46,203,0,
%T A215081 145,0,87,58,93,62,259,0,185,0,111,74,205,0,123,82,129,86,235,0,141,
%U A215081 94,371,0,265,0,159,106,413,0,295,0,177,118,183,122,469,0,335,0
%N A215081 Smallest number k such that the difference between the greatest prime divisor and the smallest prime divisor of k equals n, or 0 if there is no such k.
%C A215081 a(A007921(n)) = 0 where A007921(n) are the numbers that are not the difference of two primes.
%e A215081 a(2) = 15 because 15 = 3*5 and 5 - 3 = 2.
%p A215081 with(numtheory):for n from 0 to 65 do:ii:=0:for k from 2 to 10000 while(ii=0) do:x:=factorset(k):n1:=nops(x):d:=x[n1] - x[1]:if d=n then ii:=1: printf("%a, ", k):else fi:od:if ii=0 then printf("%a, ", 0):else fi:od:
%Y A215081 Cf. A007921.
%K A215081 nonn
%O A215081 0,1
%A A215081 _Michel Lagneau_, Aug 02 2012