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 A374813 #7 Aug 27 2024 10:11:12
%S A374813 8,9,8,5,1,9,4,1,8,2,6,6,1,1,8,8,5,6,2,7,7,8,6,3,2,4,2,0,3,5,3,8,4,3,
%T A374813 3,3,9,7,2,9,3,3,1,4,6,4,3,2,8,1,5,7,6,0,8,5,1,8,1,7,6,0,8,6,4,8,8,9,
%U A374813 6,1,7,3,8,2,1,1,8,4,1,0,8,0,3,6,1,8
%N A374813 Decimal expansion of Sum_{k>=0} cos(2k*Pi/5)/2^k.
%F A374813 Equals (49 + 3*sqrt(5))/62.
%F A374813 Equals Sum_{k>=0} cos(8 k*Pi/5)/2^k.
%F A374813 Minimal polynomial: 19 - 49 x + 31 x^2.
%F A374813 Equals 2 - 2*A373017. - _R. J. Mathar_, Aug 27 2024
%e A374813 0.8985194182661188562778632420353843339729...
%t A374813 {b, m, h} = {2, 5, 2}; s = Sum[Cos[ h k Pi/m]/b^k, {k, 0, Infinity}]
%t A374813 d = N[s, 100]
%t A374813 First[RealDigits[d], 100]
%Y A374813 Cf. A373021 (includes guide to related sequences).
%K A374813 nonn,cons
%O A374813 0,1
%A A374813 _Clark Kimberling_, Jul 20 2024