OFFSET
1,2
FORMULA
Equals Sum_{k>=0} 1 / (3^k * k!^2).
EXAMPLE
1.36216163960978990494314362841455...
MATHEMATICA
RealDigits[BesselI[0, 2/Sqrt[3]], 10, 98][[1]]
PROG
(PARI) besseli(0, 2/sqrt(3)) \\ Michel Marcus, Nov 29 2023
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Ilya Gutkovskiy, Nov 28 2023
STATUS
approved