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 A377764 #16 Nov 07 2024 09:52:18
%S A377764 1,2,6,0,5,2,9,6,1,2,8,2,9,3,8,6,4,1,0,5,5,4,5,3,6,3,3,0,1,3,5,4,0,9,
%T A377764 8,4,2,2,0,2,6,6,9,2,3,9,3,5,1,5,8,8,7,2,2,6,1,0,7,7,6,8,3,3,7,3,4,3,
%U A377764 3,9,2,6,0,5,9,0,0,9,3,5,1,1,8,8,6,7,0,5,0,7
%N A377764 Decimal expansion of (Pi/8)*exp(4*G/Pi), where G is the Catalan constant (A006752).
%H A377764 Michael Penn, <a href="https://www.youtube.com/watch?v=LG78xvZyRzU">A nice product from Ramanujan -- featuring 3 important constants!</a>, YouTube video, 2023.
%F A377764 Equals A019675*A229728.
%F A377764 Equals Product_{k >= 1} (1 - 1/(2*k+1)^2)^((-1)^k*(2*k+1)) (from Ramanujan).
%F A377764 Equals Product_{k >= 1} (1 - 1/A016754(k))^((-1)^k*A005408(k)).
%e A377764 1.26052961282938641055453633013540984220266923935...
%t A377764 First[RealDigits[Pi/8*Exp[4*Catalan/Pi], 10, 100]]
%Y A377764 Cf. A000796, A001113, A005408, A006752, A016754, A019675, A229728.
%K A377764 nonn,cons,easy
%O A377764 1,2
%A A377764 _Paolo Xausa_, Nov 06 2024