A136606 - OEIS

A136606

Reduced denominators in the Maclaurin series for the Gudermannian.

1, 6, 24, 5040, 72576, 39916800, 95800320, 1307674368000, 4184557977600, 121645100408832000, 2043637686868377600, 25852016738884976640000, 238634000666630553600000, 10888869450418352160768000000

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..14.

Eric Weisstein's World of Mathematics, Gudermannian

Eric Weisstein's World of Mathematics, Inverse Gudermannian

EXAMPLE

x - x^3/6 + x^5/24 - (61*x^7)/5040 + (277*x^9)/72576 - ...

MATHEMATICA

gd[x_] := 2*ArcTan[(E^x - 1)/(E^x + 1)]; CoefficientList[ Series[gd[x], {x, 0, 28}]/x , x^2] // Denominator (* Jean-François Alcover, Nov 09 2012 *)

CROSSREFS

Cf. A091912.

Sequence in context: A036284 A139235 A184388 * A074096 A126016 A237286

Adjacent sequences: A136603 A136604 A136605 * A136607 A136608 A136609

KEYWORD

nonn

AUTHOR

Eric W. Weisstein, Jan 12 2008

STATUS

approved