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 A292863 #9 Feb 16 2025 08:33:51
%S A292863 3,5,9,8,9,2,6,7,8,2,0,3,6,5,2,8,9,9,3,3,9,4,3,0,2,6,5,5,4,2,3,2,2,6,
%T A292863 8,4,1,3,7,9,8,2,4,0,4,6,9,9,2,8,6,5,6,5,6,7,6,0,7,3,6,6,0,8,1,5,2,1,
%U A292863 9,8,2,6,7,4,7,9,1,8,0,7,4,3,5,2,9,9,5,9,1,2,0,5,4,3,6,6,9,7,9,7,8,2,8,5,3,9
%N A292863 Decimal expansion of Product_{k>=1} (1 - exp(-Pi*k/4)).
%H A292863 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/DedekindEtaFunction.html">Dedekind Eta Function</a>
%H A292863 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/q-PochhammerSymbol.html">q-Pochhammer Symbol</a>
%H A292863 Wikipedia, <a href="https://en.wikipedia.org/wiki/Dedekind_eta_function">Dedekind eta function</a>
%H A292863 Wikipedia, <a href="https://en.wikipedia.org/wiki/Euler_function">Euler function</a>
%F A292863 Equals (6*sqrt(22*sqrt(2)-24) - 16)^(1/8) * exp(Pi/96)* Gamma(1/4) / (2*Pi^(3/4)).
%e A292863 0.359892678203652899339430265542322684137982404699286565676073660815219...
%t A292863 RealDigits[(6*Sqrt[22*Sqrt[2] - 24] - 16)^(1/8) * E^(Pi/96) * Gamma[1/4] / (2*Pi^(3/4)), 10, 120][[1]]
%t A292863 RealDigits[QPochhammer[E^(-Pi/4)], 10, 120][[1]]
%Y A292863 Cf. A259147, A259148, A259149, A259150, A259151, A292862, A292864, A368211.
%K A292863 nonn,cons
%O A292863 0,1
%A A292863 _Vaclav Kotesovec_, Sep 25 2017