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 A190240 #9 Dec 27 2017 01:37:17
%S A190240 5,10,15,20,21,25,26,29,30,31,34,35,36,39,40,41,42,44,45,46,47,49,50,
%T A190240 51,52,53,54,58,63,68,73,77,78,79,82,83,84,87,88,89,92,93,94,97,98,99,
%U A190240 100,102,103,104,105,106,107,108,116,121,126,130,131,135,136,137,140,141,142,145,146,147,150,151,152,153,154,155,156,157
%N A190240 Positions of 0 at A190239; complement of A190241.
%H A190240 G. C. Greubel, <a href="/A190240/b190240.txt">Table of n, a(n) for n = 1..5500</a>
%t A190240 u = Exp[Pi/2]; v = 1/u;
%t A190240 f[n_] := Floor[n*u + n*v] - Floor[n*u] - Floor[n*v]
%t A190240 t = Table[f[n], {n, 1, 120}] (*A190239*)
%t A190240 Flatten[Position[t, 0]] (*A190240*)
%t A190240 Flatten[Position[t, 1]] (*A190241*)
%Y A190240 Cf. A190239, A190241.
%K A190240 nonn
%O A190240 1,1
%A A190240 _Clark Kimberling_, May 06 2011