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A009181

Expansion of cosh(x)/cos(sin(x)).

1, 2, 8, 8, -960, -22400, 251008, 53882624, 2088660992, -173107810304, -34807275798528, -1238452597522432, 561542864118906880, 119928087297015742464, -1488492672130035744768, -6684251211519983379283968, -1421114720526402152671739904

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OFFSET

0,2

LINKS

Table of n, a(n) for n=0..16.

MATHEMATICA

With[{nn=40}, Take[CoefficientList[Series[Cosh[x]/Cos[Sin[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, May 01 2015 *)

CROSSREFS

Sequence in context: A083523 A202619 A202379 * A009666 A012346 A012649

Adjacent sequences: A009178 A009179 A009180 * A009182 A009183 A009184

KEYWORD

sign

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997

More terms from and prior Mathematica program replaced by Harvey P. Dale, May 01 2015

STATUS

approved

URL: https://oeis.org/A009181

⇱ A009181 - OEIS