OFFSET
0,2
FORMULA
Equals Sum_{k>=0} (-2)^k / k!^2.
EXAMPLE
-0.19654809527046820004079337208793223...
MATHEMATICA
RealDigits[BesselJ[0, 2 Sqrt[2]], 10, 100][[1]]
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Ilya Gutkovskiy, Nov 28 2023
STATUS
approved