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A099617 Denominators of coefficients in expansion of sec(x) + tan(x). 4
1, 1, 2, 3, 24, 15, 720, 315, 8064, 2835, 3628800, 155925, 95800320, 6081075, 87178291200, 638512875, 4184557977600, 10854718875, 6402373705728000, 1856156927625, 97316080327065600, 194896477400625, 1124000727777607680000, 2900518163668125, 9545360026665222144000 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..24.

L. Euler, On the sums of series of reciprocals, par. 13.

L. Euler, De summis serierum reciprocarum, E41, par. 13.

EXAMPLE

1 + x + 1/2*x^2 + 1/3*x^3 + 5/24*x^4 + 2/15*x^5 + 61/720*x^6 + 17/315*x^7 + ...

1, 1, 1/2, 1/3, 5/24, 2/15, 61/720, 17/315, 277/8064, 62/2835, 50521/3628800, 1382/155925, 540553/95800320, ... = A099612/A099617

MATHEMATICA

nn = 24; Denominator[CoefficientList[Series[Sec[x] + Tan[x], {x, 0, nn}], x]] (* T. D. Noe, Jul 24 2013 *)

CROSSREFS

Cf. A099612.

Sequence in context: A119619 A170909 A160606 * A092043 A055067 A037319

Adjacent sequences:  A099614 A099615 A099616 * A099618 A099619 A099620

KEYWORD

nonn,frac

AUTHOR

N. J. A. Sloane, Nov 19 2004

STATUS

approved

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Last modified April 21 08:30 EDT 2014. Contains 240824 sequences.