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A248617
Decimal expansion of the solution when Gudermannian(x) equals 1.
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.
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
KEYWORD
nonn,cons
AUTHOR
Robert G. Wilson v, Oct 09 2014
STATUS
approved