logs    <pi->
 1.0   0.264936
 1.1   0.357408
 1.2   0.473552
 1.3   0.607725
 1.4   0.747271
 1.5   0.884362
 1.6   1.021390
 1.7   1.165860
 1.8   1.322900
 1.9   1.492020
 2.0   1.671010
 2.1   1.857170
 2.2   2.047940
 2.3   2.242220
 2.4   2.439460
 2.5   2.641700
 2.6   2.849610
 2.7   3.068480
 2.8   3.298570
 2.9   3.540290
 3.0   3.789540
 3.1   4.050440
 3.2   4.320030
 3.3   4.596250
 3.4   4.877810
 3.5   5.164840
 3.6   5.454650