OFFSET
0,1
LINKS
Robert Price, Table of n, a(n) for n = 0..10000
Eric Weisstein's World of Mathematics, Exponential Integral.
Wikipedia, Exponential integral.
FORMULA
Equals log(A070769). - Amiram Eldar, Aug 14 2020
Equals root x of li(exp(x)/x)=0 where li(x) is the logarithmic integral. - Artur Jasinski, Apr 19 2022
EXAMPLE
0.372507410781366634461991866580119133535689497771654...
MATHEMATICA
RealDigits[ x /. FindRoot[ ExpIntegralEi[x] == 0, {x, 1}, WorkingPrecision -> 102]][[1]] (* Jean-François Alcover, Oct 29 2012 *)
RealDigits[x /. FindRoot[LogIntegral[Exp[x]]/x, {x, 1/3}, WorkingPrecision -> 105]][[1]] (* Artur Jasinski, Apr 19 2022 *)
PROG
(PARI) solve(x=.3, 1, real(eint1(-x))) \\ Charles R Greathouse IV, Apr 14 2014
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Eric W. Weisstein, Feb 01 2004
STATUS
approved