OFFSET
1,1
LINKS
MathOverflow, On equation f(z+1)-f(z)=f'(z)
FORMULA
First non-null solution to exp(lambda)-1=lambda in the first quadrant (real part).
Real part of -LambertW(-2, -1/e) - 1.
EXAMPLE
2.088843015613...
MATHEMATICA
lambda = -ProductLog[-2, -1/E] - 1; First[RealDigits[Re[lambda], 10, 100]]
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Jean-François Alcover, Apr 04 2014
STATUS
approved