OFFSET
2,2
FORMULA
Equals e^2 * BesselI(0,2) = e^2 * Sum_{n>=0} 1/n!^2.
Equals e^4 * Sum_{n>=0} (-1)^n * C(2n,n)/n!. - Amiram Eldar, Nov 06 2020
EXAMPLE
16.843983681258...
Equals 1/1 + 2/1 + 24/8 + 720/216 + 40320/13824 + 3628800/1728000 + ...
MATHEMATICA
RealDigits[E^2*BesselI[0, 2], 10, 100][[1]] (* Amiram Eldar, Nov 06 2020 *)
PROG
(PARI) exp(2)*besseli(0, 2) \\ Charles R Greathouse IV, Feb 19 2014
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Richard R. Forberg, Dec 31 2013
EXTENSIONS
More terms from Jon E. Schoenfield, Mar 21 2021
STATUS
approved