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 A082453 #5 Oct 15 2013 22:31:55
%S A082453 3,5,7,9,11,13,15,17,19,21,23,25,27,29,31,33,35,37,39,41,43,47,49,51,
%T A082453 53,55,57,59,61,63,65,67,69,71,73,77,79,81,83,85,87,89,91,93,95,97,99,
%U A082453 101,103,105,107,109,111,113,115,119,121,123,125,127,129,131,133,135,137
%N A082453 a(n)=2n+1 where n is such that A083344(n) is zero.
%e A082453 First two missing odd numbers are 45 and 75; missing terms are in A082452.
%t A082453 di[x_] := Apply[LCM, Divisors[x]+1] (*A066715=*)t1=Table[GCD[2*n+1, DivisorSigma[1, 2*n+1]], {n, 1, 2048}]; (*A082457=*)t2=Table[GCD[2*w+1, di[1+2*w]], {w, 1, 2048}]; (*A083344=*)t3=t2-t1; (*A082453=*)1+2*Flatten[Position[Abs[Sign[t3]], 0]];
%Y A082453 Cf. A057643, A066715, A000203, A082457, A083344.
%K A082453 nonn
%O A082453 1,1
%A A082453 _Labos Elemer_, Apr 25 2003