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 A373022 #7 Mar 30 2025 02:40:31
%S A373022 5,0,5,3,5,2,6,5,2,8,1,6,1,9,4,9,2,0,2,0,3,3,8,6,2,7,3,7,3,7,6,6,5,8,
%T A373022 4,1,3,5,7,1,0,9,3,7,5,1,0,7,5,1,8,9,3,8,0,1,7,7,8,6,0,9,5,0,0,1,6,5,
%U A373022 3,4,9,2,8,3,3,6,1,6,6,7,2,7,1,2,8,1
%N A373022 Decimal expansion of Sum_{k>=0} sin(2*k*Pi/5)/2^k.
%F A373022 Equals sqrt(2*(5 + sqrt(5)))/(12 - 2*sqrt(5)).
%F A373022 Equals (-1)*Sum_{k>=0} sin(8*k*Pi/5)/2^k.
%F A373022 Minimal polynomial: 5 - 265*x^2 + 961*x^4.
%e A373022 0.505352652816194920203386273737665...
%t A373022 {b, m, h} = {2, 5, 2}; s = Sum[Sin[ h k Pi/m]/b^k, {k, 0, Infinity}]
%t A373022 d = N[s, 100]
%t A373022 First[RealDigits[d], 100]
%Y A373022 Cf. A373021 (includes guide to related sequences).
%K A373022 nonn,cons
%O A373022 0,1
%A A373022 _Clark Kimberling_, Jul 20 2024