pub const N: usize = 10;Expand description
The truncation point of the direct sum. Ten is the knee: eight direct terms and six
correction terms leave 2.4e-14, ten and eight reach 4.4e-16, and more of either buys nothing
(12 and 8 measured 2.7e-16). Because the terms factor over the primes, the transcendental
cost is pi(10) = 4 rather than 9.