logs    <pi->
 1.0   0.258117
 1.1   0.344558
 1.2   0.452669
 1.3   0.576747
 1.4   0.704909
 1.5   0.830497
 1.6   0.955747
 1.7   1.087440
 1.8   1.230580
 1.9   1.384660
 2.0   1.547410
 2.1   1.716120
 2.2   1.888330
 2.3   2.063080
 2.4   2.240620
 2.5   2.423770
 2.6   2.612470
 2.7   2.811290
 2.8   3.020910
 2.9   3.241890
 3.0   3.470020
 3.1   3.709430
 3.2   3.957800
 3.3   4.213710
 3.4   4.475650
 3.5   4.743980
 3.6   5.015830