A131448 Denominators of n-th approximation of factorial (also called harmonic) expansion of Euler's constant gamma (A001620).

1, 2, 2, 24, 40, 144, 5040, 40320, 6048, 6048, 19958400, 53222400, 53222400, 87178291200, 118879488000, 5230697472000, 8083805184000, 3201186852864000, 40548366802944000, 2432902008176640000, 17030314057236480000

Offset

1,2

Comments

For the Havil reference and a W. Lang link see A131447.

Links

Table of n, a(n) for n=1..21.

Formula

a(n) = denominator(r(n)), with r(n) = Sum_{k=1..n} b(k)/k!, and b(k) = A096622(k) (factorial expansion of gamma).

Example

Rationals r(n): [0, 1/2, 1/2, 13/24, 23/40, 83/144, 2909/5040, 23273/40320, 3491/6048, ...]

Crossrefs

Cf. A001620, A096622, A131447 (numerators).

Sequence in context: A226243 A226979 A261517 * A156447 A272641 A334123

Adjacent sequences: A131445 A131446 A131447 * A131449 A131450 A131451

Keyword

nonn,frac,easy,changed

Author

Wolfdieter Lang, Aug 07 2007

Status

approved