A131446 Denominators of n-th approximation of factorial (also called harmonic) expansion of Pi.
1, 1, 1, 8, 15, 720, 5040, 13440, 13440, 3628800, 532224, 43545600, 691891200, 691891200, 108972864000, 1902071808000, 118562476032000, 6847458508800, 24329020081766400, 17888985354240000, 1344498478202880000
Offset: 1
Examples
Rationals r(n): [3,3,3,25/8,47/15,2261/720,15833/5040,42223/13440,42223/13440,...].
Formula
a(n) = denominator(r(n)), with r(n):=sum(b(k)/k!,n=1..n) with b(k):=A075874(k) (factorial expansion of Pi).
Comments