Benchmark: timing 30 iterations of a, b...
         a: 26 wallclock secs (26.64 usr +  0.00 sys = 26.64 CPU) @  1.13/s (n=30)
         b: 32 wallclock secs (31.64 usr +  0.00 sys = 31.64 CPU) @  0.95/s (n=30)
Benchmark: timing 30 iterations of a2, b2...
        a2: 20 wallclock secs (20.10 usr +  0.00 sys = 20.10 CPU) @  1.49/s (n=30)
        b2: 28 wallclock secs (27.25 usr +  0.00 sys = 27.25 CPU) @  1.10/s (n=30)