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

Author

Eric W. Weisstein, Jan 12 2008

Keywords

• nonn

Examples

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

References

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

Links

• Eric Weisstein's World of Mathematics, Gudermannian.
• Eric Weisstein's World of Mathematics, Inverse Gudermannian.

Crossrefs

Cf. A091912.

Programs

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 *)