A131444 Denominators of n-th approximation of factorial (also called harmonic) expansion of the golden section phi:=(1+sqrt(5))/2.

1, 2, 2, 12, 60, 60, 280, 40320, 22680, 3628800, 1900800, 479001600, 6227020800, 6227020800, 1307674368000, 1307674368000, 13680285696000, 582033973248000, 24329020081766400, 2432902008176640000

Offset

1,2

Comments

Numerators are given in A131443.

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

Links

Table of n, a(n) for n=1..20.

Formula

a(n)=denominator(r(n)), with r(n):=sum(b(k)/k!,n=1..n) with b(k):=A068451(k).

Example

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

Crossrefs

Sequence in context: A349529 A173842 A352526 * A291541 A180072 A367546

Adjacent sequences: A131441 A131442 A131443 * A131445 A131446 A131447

Keyword

nonn,frac,easy

Author

Wolfdieter Lang Aug 07 2007

Status

approved