The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A012388 arcsin(tan(x)*tan(x))=2/2!*x^2+16/4!*x^4+392/6!*x^6+21376/8!*x^8... 1
 0, 2, 16, 392, 21376, 2117792, 333550336, 76433892992, 23981418704896, 9862199971860992, 5144452992189485056, 3317894031273853601792, 2591931617534673513250816, 2411532576645611695219515392 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Table of n, a(n) for n=0..13. FORMULA a(n) ~ 2^(4*n-1) * (2*n)! / (n^(3/2) * Pi^(2*n)). - Vaclav Kotesovec, Feb 08 2015 MATHEMATICA nn = 20; Table[(CoefficientList[Series[ArcSin[Tan[x]^2], {x, 0, 2*nn}], x] * Range[0, 2*nn]!)[[n]], {n, 1, 2*nn+1, 2}] (* Vaclav Kotesovec, Feb 08 2015 *) CROSSREFS Sequence in context: A295710 A012390 A009613 * A297368 A012752 A188904 Adjacent sequences: A012385 A012386 A012387 * A012389 A012390 A012391 KEYWORD nonn AUTHOR Patrick Demichel (patrick.demichel(AT)hp.com) EXTENSIONS a(0)=0 prepended by Vaclav Kotesovec, Feb 08 2015 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 3 22:46 EDT 2023. Contains 363116 sequences. (Running on oeis4.)