Method 6: 14 wallclock secs (14.31 usr +  0.01 sys = 14.32 CPU)
Method 7: 15 wallclock secs (14.28 usr +  0.01 sys = 14.29 CPU)
Method 8: 14 wallclock secs (14.25 usr +  0.01 sys = 14.26 CPU)