OFFSET
1,1
FORMULA
Equals Product_{k>=0} (1 + 1/(2*k*(k + 1) + 1)).
Equals Product_{k>=0} (1 + 1/A001844(k)).
EXAMPLE
3.040191551642553075601860027900757233823854905879...
MATHEMATICA
RealDigits[Cosh[Sqrt[3] Pi/2] Sech[Pi/2], 10, 120][[1]]
PROG
(PARI) cosh(sqrt(3)*Pi/2)/cosh(Pi/2) \\ Michel Marcus, Jun 20 2019
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Ilya Gutkovskiy, Jun 19 2019
STATUS
approved