> restart:

> alias(W=LambertW);

[Maple Math]

> [seq( W(k,-0.5), k=-6..5)];

[Maple Math]
[Maple Math]
[Maple Math]
[Maple Math]
[Maple Math]
[Maple Math]

> plot( map( t->[evalc(Re(t)),evalc(Im(t))], % ), style=POINT);

[Maple Plot]

> with(plots):

> N := 100:

> p := array(1..N):

> for i to N do

> p[i] := plot( map( t->[evalc(Re(t)),evalc(Im(t))],
[seq( W(k, -i*exp(-1)/20),k=-6..5)] )):

> od:

> display([seq(p[i],i=1..N)],insequence=true,style=POINT);

[Maple Plot]

> exp(-1)/20*n= Pi/2;

[Maple Math]

> fsolve(%,n);

[Maple Math]

>