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A227574 Denominators of rationals with e.g.f. D(4,x), a Debye function. 3
1, 5, 9, 1, 60, 1, 105, 1, 90, 1, 231, 1, 10920, 1, 27, 1, 2550, 1, 4389, 1, 1980, 1, 897, 1, 19110, 1, 45, 1, 6960, 1, 121737, 1, 4590, 1, 57, 1, 19191900, 1, 63, 1, 148830, 1, 20769, 1, 8280, 1, 3525, 1, 603330, 1, 891, 1, 22260, 1, 11571, 1, 13050, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

See the comments and the Abramowitz-Stegun link under A227573.

LINKS

Table of n, a(n) for n=0..57.

FORMULA

a(n) = denominator(4*B(n)/(n+4)), n >= 0, with the Bernoulli numbers B(n) = A027641(n)/A027642(n).

The e.g.f. of the rationals r(4,n) := 4*B(n)/(n+4) is D(4,x) = (4/x^4)*int(t^4/(exp(t) - 1), t=0..x).

EXAMPLE

The rationals r(4,n), n=0..15 are: 1, -2/5, 1/9, 0, -1/60, 0, 1/105, 0, -1/90, 0, 5/231, 0, -691/10920, 0, 7/27, 0.

CROSSREFS

Cf. A227573, A027641/A027642, A120086/A120087 (D(4,x) as o.g.f.).

Sequence in context: A266553 A306980 A063921 * A214869 A021632 A248191

Adjacent sequences:  A227571 A227572 A227573 * A227575 A227576 A227577

KEYWORD

nonn,easy,frac

AUTHOR

Wolfdieter Lang, Jul 17 2013

STATUS

approved

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Last modified October 21 16:25 EDT 2019. Contains 328302 sequences. (Running on oeis4.)