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 A373023 #7 Mar 30 2025 02:40:34
%S A373023 3,0,5,0,1,8,0,0,8,0,5,4,6,3,8,9,9,2,3,6,5,8,0,1,1,0,7,4,2,9,0,9,1,0,
%T A373023 7,1,4,5,8,5,0,7,4,5,9,4,7,1,0,8,3,3,9,7,3,0,8,6,1,3,0,8,5,7,7,7,4,3,
%U A373023 6,8,2,9,4,4,1,9,7,7,5,6,1,8,4,3,5,2
%N A373023 Decimal expansion of Sum_{k>=0} sin(3*k*Pi/5)/2^k.
%F A373023 Equals sqrt(2*(5 + sqrt(5)))/(8 + 2*sqrt(5)).
%F A373023 Equals (-1)*Sum_{k>=0} sin(7*k*Pi/5)/2^k.
%F A373023 Minimal polynomial: 5 - 65*x^2 + 121*x^4.
%e A373023 0.30501800805463899236580110742909107145...
%t A373023 {b, m, h} = {2, 5, 3}; s = Sum[Sin[ h k Pi/m]/b^k, {k, 0, Infinity}]
%t A373023 d = N[s, 100]
%t A373023 First[RealDigits[d], 100]
%Y A373023 Cf. A373021 (includes guide to related sequences).
%K A373023 nonn,cons
%O A373023 0,1
%A A373023 _Clark Kimberling_, Jul 20 2024