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 A166053 #2 Mar 31 2012 13:21:20
%S A166053 11,319,607,703,895,1063,1103,1135,1447,1495,2287,2383,2543,3223,3967,
%T A166053 4255,4615,4807,5143,5207,5407,5695,5783,5983,6247,6487,6607,6799,
%U A166053 6943,7495,7927,8503,9103,9127,9655,10183,10615,10735,12055,13207
%N A166053 Integers of the form 4n+3 for which Sum_{i=1..u} J(i,4n+3) obtains value zero exactly 3 times, when u ranges from 1 to (4n+3). Here J(i,k) is the Jacobi symbol.
%C A166053 Second row of A166092.
%Y A166053 a(n) = A004767(A166052(n)).
%K A166053 nonn
%O A166053 1,1
%A A166053 _Antti Karttunen_, Oct 08 2009