A344505 Decimal expansion of (exp(2*Pi) - 1) / (exp(2*Pi) + 1).

9, 9, 6, 2, 7, 2, 0, 7, 6, 2, 2, 0, 7, 4, 9, 9, 4, 4, 2, 6, 4, 6, 9, 0, 5, 8, 0, 0, 1, 2, 5, 3, 6, 7, 1, 1, 8, 9, 6, 8, 9, 9, 1, 9, 0, 8, 0, 4, 5, 8, 7, 6, 1, 4, 3, 6, 2, 6, 1, 2, 4, 1, 5, 9, 7, 8, 5, 4, 1, 2, 9, 8, 9, 8, 2, 8, 2, 1, 7, 1, 7, 6, 8, 5, 2, 8

Offset

0,1

Links

Table of n, a(n) for n=0..85.

Formula

Equals tanh(Pi).

Equals 1 / A175316.

Equals A175315 / A175314.

Equals 1 - 2/(1 + (Sum_{k>=0} 1/k!)^tau), where tau = 2*Pi = A019692.

Example

Approximate 0.9962720762207499442646905800...
Approximate tau/(2 + tau^2/(6 + tau^2/(10 + tau^2/(14 + tau^2/(18 + tau^2/(22 + tau^2/(26 + tau^2/(30 + ...)))))))), where tau = 2*Pi.

Maple

Digits := 100: tau := 2*Pi: (exp(tau) - 1)/(exp(tau) + 1):
evalf(%)*10^86: ListTools:-Reverse(convert(floor(%), base, 10));

Mathematica

RealDigits[Tanh[Pi], 10, 100][[1]] (* Amiram Eldar, May 22 2021 *)

Crossrefs

Cf. A019692, A175314, A175315, A175316.

Sequence in context: A019894 A347150 A346850 * A334478 A262823 A157293

Adjacent sequences: A344502 A344503 A344504 * A344506 A344507 A344508

Keyword

nonn,cons

Author

Peter Luschny, May 22 2021

Status

approved