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A131444
Denominators of n-th approximation of factorial (also called harmonic) expansion of the golden section phi:=(1+sqrt(5))/2.
1
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.
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
KEYWORD
nonn,frac,easy
AUTHOR
Wolfdieter Lang Aug 07 2007
STATUS
approved