login
Denominators of n-th approximation of factorial (also called harmonic) expansion of the golden ratio phi (A001622).
1

%I #12 Jan 28 2025 10:42:01

%S 1,2,2,12,60,60,280,40320,22680,3628800,1900800,479001600,6227020800,

%T 6227020800,1307674368000,1307674368000,13680285696000,

%U 582033973248000,24329020081766400,2432902008176640000

%N Denominators of n-th approximation of factorial (also called harmonic) expansion of the golden ratio phi (A001622).

%C For the rationals r(n) see the W. Lang link found under A131443.

%F a(n) = denominator(r(n)), with r(n) = Sum_{k=1..n} b(k)/k!, with b(k) = A068451(k).

%e Rationals r(n):[1, 3/2, 3/2, 19/12, 97/60, 97/60, 453/280, 65239/40320,...].

%Y Cf. A001622, A068451, A131443 (numerators).

%K nonn,frac,easy

%O 1,2

%A _Wolfdieter Lang_, Aug 07 2007