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 A323482 #29 Jan 30 2022 15:58:11
%S A323482 1,2,6,4,4,9,9,7,8,0,3,4,8,4,4,4,2,0,9,1,9,1,3,1,9,7,4,7,2,5,5,4,9,8,
%T A323482 4,8,2,5,5,7,6,9,6,9,9,8,8,5,7,5,2,5,6,2,6,5,6,6,2,3,7,9,6,0,2,6,5,8,
%U A323482 7,5,6,7,9,7,6,6,0,0,7,0,8,5,0,6,1,9
%N A323482 Decimal expansion of 1/2 + 1/3 + 1/5 + ... + 1/(2^n + 1) + ...
%H A323482 Jinyuan Wang, <a href="/A323482/b323482.txt">Table of n, a(n) for n = 1..1000</a>
%F A323482 From _Amiram Eldar_, Jun 30 2020: (Start)
%F A323482 Equals 1/2 + Sum_{k>=1} (-1)^(k+1)/(2^k-1)
%F A323482 Equals Sum_{k>=1} (mu(k) - (-1)^k)/(2^k-1), where mu is the Möbius function (A008683).
%F A323482 Equals (1 + A179951)/2. (End)
%F A323482 Equals (1/2) + Sum_{n >= 1} (-1)^(n+1)*((4^n + 1)/(4^n - 1))*(1/2)^(n^2). The first 18 terms of the series gives the constant correct to more than 100 decimal places. - _Peter Bala_, Jan 28 2022
%e A323482 1.2644997803484442091913...
%p A323482 evalf((1/2) + add( (-1)^(n+1)*((4^n + 1)/(4^n - 1))*(1/2)^(n^2), n = 1..18), 100); # _Peter Bala_, Jan 28 2022
%t A323482 s = Sum[1/(2^k + 1), {k, 0, Infinity}]
%t A323482 r = N[Re[s], 200]
%t A323482 RealDigits[r][[1]]
%o A323482 (PARI) suminf(k=0, 1/(2^k+1)) \\ _Michel Marcus_, Jan 15 2019
%Y A323482 Cf. A000051, A065442, A008683, A179951.
%K A323482 nonn,cons
%O A323482 1,2
%A A323482 _Clark Kimberling_, Jan 15 2019