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A364521
Decimal expansion of the solution to Ei(x) = x.
0
5, 2, 7, 6, 1, 2, 3, 4, 7, 2, 0, 1, 7, 4, 2, 0, 6, 0, 5, 1, 6, 9, 1, 5, 8, 5, 1, 3, 8, 0, 5, 1, 8, 7, 2, 1, 6, 9, 1, 6, 4, 1, 7, 6, 4, 1, 6, 1, 5, 2, 5, 4, 7, 3, 1, 6, 8, 8, 7, 3, 3, 2, 9, 0, 3, 3, 1, 0, 1, 3, 4, 2, 7, 7, 7, 4, 6, 6, 7, 5, 2, 4, 5, 7, 8, 0, 5, 2, 5, 8, 4, 7, 5, 0, 7, 8, 6, 1, 4, 4, 7
OFFSET
0,1
COMMENTS
Fixed point of exponential integral.
LINKS
Eric Weisstein's World of Mathematics, Exponential Integral.
EXAMPLE
0.5276123472017420...
MAPLE
Digits:=101: fsolve(Ei(1, x)-x, x);
MATHEMATICA
RealDigits[FindRoot[ExpIntegralE[1, x] - x, {x, 0.5}, WorkingPrecision -> 101][[1, 2]], 10, 101][[1]]
PROG
(PARI) default(realprecision, 101); solve(x=0.5, 0.6, eint1(x)-x)
(PARI) solve(x=0.5, 0.6, -Euler()-log(x)-suminf(k=1, (-x)^k/(k*k!))-x)
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Michal Paulovic, Aug 15 2023
STATUS
approved