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

1,2

Comments

Inverse of A248618.

Links

Table of n, a(n) for n=1..105.

Wikipedia, Gudermannian function.

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)

Example

1.22619117088351707081306096747190675272424835022074027913861684354298467624428...

Maple

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

Mathematica

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

Crossrefs

Cf. A248618.

Sequence in context: A155818 A010245 A154196 * A225975 A016529 A077894

Adjacent sequences: A248614 A248615 A248616 * A248618 A248619 A248620

Keyword

nonn,cons

Author

Robert G. Wilson v, Oct 09 2014

Status

approved