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A299625 Decimal expansion of e^(2*W(2)) = 4/(W(2))^2, where W is the Lambert W function (or PowerLog); see Comments. 3
5, 5, 0, 2, 5, 4, 6, 6, 0, 4, 2, 2, 0, 7, 2, 4, 0, 7, 5, 3, 1, 1, 2, 6, 8, 1, 3, 5, 9, 4, 9, 3, 2, 6, 0, 1, 9, 5, 5, 3, 8, 4, 3, 4, 8, 0, 0, 7, 2, 8, 3, 1, 7, 5, 2, 0, 4, 0, 1, 5, 0, 2, 8, 4, 7, 3, 0, 5, 8, 9, 6, 0, 9, 9, 9, 6, 7, 2, 8, 7, 6, 7, 4, 0, 2, 7 (list; constant; graph; refs; listen; history; text; internal format)
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^(2*W(2)) = 4/(W(2))^2.  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^(2*W(2)) = 5.50254660422072407531126813594932...

MATHEMATICA

w[x_] := ProductLog[x]; x = 2; y = 2;

N[E^(w[x] + w[y]), 130]   (* A299625 *)

RealDigits[(2/LambertW[2])^2, 10, 100][[1]] (* G. C. Greubel, Mar 03 2018 *)

PROG

(PARI) (2/lambertw(2))^2 \\ G. C. Greubel, Mar 03 2018

CROSSREFS

Cf. A299613, A299624.

Sequence in context: A176144 A308356 A065936 * A021649 A200257 A236023

Adjacent sequences:  A299622 A299623 A299624 * A299626 A299627 A299628

KEYWORD

nonn,cons,easy

AUTHOR

Clark Kimberling, Mar 03 2018

STATUS

approved

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Last modified July 24 00:28 EDT 2021. Contains 346265 sequences. (Running on oeis4.)