- 87 名前：１３２人目の素数さん mailto:sage [2018/09/19(水) 03:39:38.95 ID:Ck89eeKN.net]
- >>82
log C[2n n]
= log 2n! - 2logn!
〜(1/2)log(4πn)+2n log(2n/e) - log2πn-2nlog(n/e)
= (1/2)log(4π)+(1/2)log(n)+2n log(n)+2n log(2)-2n - log2π- log n-2nlog(n)
= -(1/2)log(n) + 2n log(2) - (1/2)logπ
= log (4^n/√(πn))
