OFFSET
1,1
COMMENTS
The Lambert W function satisfies the functional equation e^(W(x) + W(y)) = x*y/(W(x)*W(y)) for x and y greater than -1/e, so that e^(W(1) + W(3)) = 3/(W(1)*W(3)). See A299613 for a guide to related constants.
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Lambert W-Function
EXAMPLE
e^(W(1) + W(3)) = 5.03821667615918674918541702644888...
MATHEMATICA
w[x_] := ProductLog[x]; x = 1; y = 3;
N[E^(w[x] + w[y]), 130] (* A299621 *)
RealDigits[3/(LambertW[1]*LambertW[3]), 10, 100][[1]] (* G. C. Greubel, Mar 03 2018 *)
PROG
(PARI) 3/(lambertw(1)*lambertw(3)) \\ G. C. Greubel, Mar 03 2018
CROSSREFS
KEYWORD
AUTHOR
Clark Kimberling, Mar 01 2018
STATUS
approved