A248617 Decimal expansion of the solution when Gudermannian(x) equals 1.

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

Offset: 1

Author

Robert G. Wilson v, Oct 09 2014

Keywords

• nonn
• cons

Comments

Inverse of A248618.

Examples

			1.22619117088351707081306096747190675272424835022074027913861684354298467624428...
		

Links

• Wikipedia, Gudermannian function.

Crossrefs

Cf. A248618.

Programs

Maple

evalf(log(tan((2+Pi)/4)),100) # Vaclav Kotesovec, Oct 11 2014

Mathematica

RealDigits[ InverseGudermannian[ 1], 10, 111][[1]]

Formula

Equals log(tan((2+Pi)/4)). - Vaclav Kotesovec, Oct 11 2014

From Amiram Eldar, Apr 07 2022: (Start)

Equals 2*arctanh(tan(1/2)).

Equals Integral_{x=0..1} sec(x) dx. (End)