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 A135560 #15 Jul 07 2022 02:02:36
%S A135560 2,3,1,4,1,2,1,5,1,2,1,3,1,2,1,6,1,2,1,3,1,2,1,4,1,2,1,3,1,2,1,7,1,2,
%T A135560 1,3,1,2,1,4,1,2,1,3,1,2,1,5,1,2,1,3,1,2,1,4,1,2,1,3,1,2,1,8,1,2,1,3,
%U A135560 1,2,1,4,1,2,1,3,1,2,1,5,1,2,1,3,1,2,1,4,1,2,1,3,1,2,1,6,1,2,1,3,1,2,1,4,1
%N A135560 a(n) = A007814(n) + A036987(n-1) + 1.
%H A135560 Reinhard Zumkeller, <a href="/A135560/b135560.txt">Table of n, a(n) for n = 1..10000</a>
%F A135560 a(2^k) = k+2; a(2^k + 2^(k-1)) = k. - _Reinhard Zumkeller_, Mar 02 2008
%t A135560 a[n_] := 1 + IntegerExponent[n, 2] + Sum[(-1)^(n - k - 1)*Binomial[n - 1, k]* Sum[Binomial[k, 2^j - 1], {j, 0, k}], {k, 0, n - 1}]; Table[a[n], {n, 1, 25}] (* _G. C. Greubel_, Oct 17 2016 *)
%o A135560 (PARI) a(n)=my(t=valuation(n, 2)); t + (n==2^t) + 1 \\ _Charles R Greathouse IV_, Oct 17 2016
%o A135560 (Python)
%o A135560 def A135560(n): return (m:=(~n & n-1)).bit_length()+int(m==n-1)+1 # _Chai Wah Wu_, Jul 06 2022
%Y A135560 Cf. A007814, A036987, A091090, A135534, A135561.
%K A135560 nonn,easy
%O A135560 1,1
%A A135560 _N. J. A. Sloane_, Mar 01 2008
%E A135560 More terms from _Reinhard Zumkeller_, Mar 02 2008