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 A074766 #15 Mar 04 2017 13:51:42
%S A074766 -2,-1,0,1,2,5,2,7,6,3,6,3,6,7,4,9,4,11,10,11,14,13,10,21,10,11,18,21,
%T A074766 24,25,8,17,10,25,16,21,22,19,24,23,22,29,18,27,24,35,22,9,18,33,40,
%U A074766 39,42,37,32,31,24,41,34,37,46,35,24,33,42,43,28,27,24,41,44,37,32,37,30,39,32
%N A074766 a(n) = prime(2n) - 2*prime(n) - n.
%C A074766 Conjecture: p(2n) - 2p(n) < 2n for all n.
%F A074766 a(n) = A066066(n) - n.
%e A074766 a(9) = p(18) - 2p(9) - 9 = 61 - 2*23 - 9 = 6.
%p A074766 A074766:=n->ithprime(2*n)-2*ithprime(n)-n: seq(A074766(n), n=1..100); # _Wesley Ivan Hurt_, Jan 16 2017
%t A074766 Table[Prime[2 n] - 2 Prime[n] - n, {n, 80}] (* _Harvey P. Dale_, Mar 04 2017 *)
%Y A074766 Cf. A066066.
%K A074766 sign
%O A074766 1,1
%A A074766 _Werner D. Sand_, Sep 29 2002