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 A135534 #13 Jul 06 2022 19:40:16
%S A135534 1,3,0,7,0,1,0,15,0,1,0,3,0,1,0,31,0,1,0,3,0,1,0,7,0,1,0,3,0,1,0,63,0,
%T A135534 1,0,3,0,1,0,7,0,1,0,3,0,1,0,15,0,1,0,3,0,1,0,7,0,1,0,3,0,1,0,127,0,1,
%U A135534 0,3,0,1,0,7,0,1,0,3,0,1,0,15,0,1,0,3,0,1,0,7,0,1,0,3,0,1,0,31,0,1,0,3,0,1
%N A135534 a(1) = 1; for n>=1, a(2n) = A135561(n), a(2n+1) = 0.
%H A135534 Antti Karttunen, <a href="/A135534/b135534.txt">Table of n, a(n) for n = 1..65537</a>
%p A135534 GS(6,1,200); [see A135416].
%o A135534 (PARI)
%o A135534 A135560(n) = { my(t=valuation(n, 2)); (t + (n==2^t) + 1); }; \\ From A135560
%o A135534 A135534(n) = if(1==n,1,if((n%2),0,((2^(A135560(n/2)))-1))); \\ _Antti Karttunen_, Sep 27 2018
%o A135534 (Python)
%o A135534 def A135534(n): return 1 if n == 1 else 0 if n&1 else (1<<(m:=(~(k:=n>>1) & k-1)).bit_length()+int(m==k-1)+1)-1 # _Chai Wah Wu_, Jul 06 2022
%Y A135534 Cf. A135416.
%Y A135534 This is Guy Steele's sequence GS(6, 1) (see A135416).
%K A135534 nonn
%O A135534 1,2
%A A135534 _N. J. A. Sloane_, based on a message from Guy Steele and _Don Knuth_, Mar 01 2008