In floats (i.e. numer:true) we have:
(%i1) x:makelist(1/5^k,k,1,7);
(%o1) [0.2,0.04,0.008,0.0016,3.2000000000000003E-4,6.3999999999999997E-5,
1.2799999999999999E-5]
but Firefox-javascript (for example) returns precise values:
0.2
0.04
0.008
0.0016
0.00032
etc. (at least up to k=20)
Limits of the FLOAT in Maxima and Firefox are the same: 1e-324 - 1e309
(Windows XP, Maxima 5.27.0, Firefox 11.0)