A136606 Reduced denominators in the Maclaurin series for the Gudermannian.

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

Offset

1,2

References

Jerome Spanier and Keith B. Oldham, "Atlas of Functions", Hemisphere Publishing Corp., 1987, chapter 33, equation 33:14:14 at page 318.

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,changed

Author

Eric W. Weisstein, Jan 12 2008

Status

approved