OFFSET
0,1
REFERENCES
Calvin C. Clawson, Mathematical Mysteries: The Beauty and Magic of Numbers, Springer, 2013. See p. 225.
FORMULA
Equals (e^Pi - 1)/(e^Pi + 1) = K_{n>0} Pi^(2-[n=1])/(4*n - 2) (see Clawson at p. 225). - Stefano Spezia, Jul 01 2024
EXAMPLE
0.91715233566727434637309...
MAPLE
evalf(tanh(Pi/2)) ;
MATHEMATICA
First[RealDigits[Tanh[Pi/2], 10, 100]] (* Paolo Xausa, Dec 06 2023 *)
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
R. J. Mathar, Dec 06 2023
STATUS
approved