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 A102047 #17 Feb 16 2025 08:32:55
%S A102047 0,9,6,5,7,3,5,9,0,2,7,9,9,7,2,6,5,4,7,0,8,6,1,6,0,6,0,7,2,9,0,8,8,2,
%T A102047 8,4,0,3,7,7,5,0,0,6,7,1,8,0,1,2,7,6,2,7,0,6,0,3,4,0,0,0,4,7,4,6,6,9,
%U A102047 6,8,1,0,9,8,4,8,4,7,3,5,7,8,0,2,9,3,1,6,6,3,4,9,8,2,0,9,3,4,3,7,7,1,0
%N A102047 Decimal expansion of -1/4 + log(2)/2.
%H A102047 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/AbelsIntegral.html">Abel's Integral</a>.
%H A102047 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CosineIntegral.html">Cosine Integral</a>.
%H A102047 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>
%F A102047 Equals A016655/10 - 1/4. - _R. J. Mathar_, Dec 13 2008
%F A102047 From _Amiram Eldar_, Sep 08 2020: (Start)
%F A102047 Equals Sum_{k>=1} (-1)^(k+1)/((2*k+1)^2-1).
%F A102047 Equals Sum_{k>=1} Ci((2*k-1)*Pi), where Ci(x) is the cosine integral.
%F A102047 Equals Integral_{x=1..oo} log(x)/(x+1)^3 dx. (End)
%e A102047 -1/4 + log(2)/2 = 0.0965735902...
%t A102047 RealDigits[Log[2]/2 - 1/4, 10, 100][[1]] (* _Amiram Eldar_, Sep 08 2020 *)
%o A102047 (PARI) log(2)/2 - 1/4 \\ _Charles R Greathouse IV_, May 15 2019
%Y A102047 Cf. A016655.
%K A102047 nonn,cons
%O A102047 0,2
%A A102047 _Eric W. Weisstein_, Dec 26 2004