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 A167393 #7 Nov 03 2015 17:03:10 %S A167393 0,1,1,1,1,1,1,0,1,0,1,0,1,0,0,1,0,0,1,0,0,0,1,0,0,0,0,1,0,0,0,0,1,0, %T A167393 0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,0,0,0, %U A167393 0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1 %N A167393 Characteristic function of the range of A000009. %C A167393 a(A000009(n)) = 1; a(A167377(n)) = 0. %H A167393 Reinhard Zumkeller, <a href="/A167393/b167393.txt">Table of n, a(n) for n = 0..10000</a> %H A167393 <a href="/index/Ch#char_fns">Index entries for characteristic functions</a> %o A167393 (Haskell) %o A167393 import Data.List.Ordered (member) %o A167393 a167393 = fromEnum . flip member a000009_list %o A167393 -- _Reinhard Zumkeller_, Nov 03 2015 %Y A167393 Cf. A000009, A167377, A167392. %K A167393 nonn %O A167393 0,1 %A A167393 _Reinhard Zumkeller_, Nov 03 2009