A227574 - OEIS

A227574

Denominators of rationals with e.g.f. D(4,x), a Debye function.

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

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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.