OFFSET
0,1
COMMENTS
The Pierce Expansion of this number is the squares > 1: 4,9,16,25,... - Franklin T. Adams-Watters, May 22 2006
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..2500
Eric Weisstein's World of Mathematics, Factorial Sums
Eric Weisstein's World of Mathematics, Pierce Expansion
FORMULA
Equals Sum_{k>=0} (-1)^k/(k!)^2.
Continued fraction expansion: BesselJ(0,2) = 1/(4 + 4/(8 + 9/(15 + ... + (n - 1)^2/(n^2 + 1 + ...)))). See A073701 for a proof. - Peter Bala, Feb 01 2015
Equals BesselI(0,2*i), where BesselI is the modified Bessel function of order 0. - Jianing Song, Sep 18 2021
EXAMPLE
0.223890779...
MATHEMATICA
RealDigits[N[BesselJ[0, 2], 250]][[1]] (* G. C. Greubel, Dec 26 2016 *)
PROG
(PARI) besselj(0, 2) \\ Charles R Greathouse IV, Feb 19 2014
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Eric W. Weisstein, Jan 28 2004
STATUS
approved