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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A009375 Expansion of log(1+tan(x)*cosh(x)). 0

%I #15 Jun 22 2015 22:23:22

%S 0,1,-1,7,-26,165,-1216,10827,-111376,1316585,-17441536,257028847,

%T -4164440576,73616009805,-1409649350656,29070305745267,

%U -642306123237376,15137914082015825,-379068323095576576,10050622525103392087

%N Expansion of log(1+tan(x)*cosh(x)).

%F a(n) ~ (n-1)! * (-1)^(n+1) / r^n, where r = 0.678886646361824692174613333109767742222867349... is the root of the equation cosh(r)*tan(r) = 1. - _Vaclav Kotesovec_, Jan 24 2015

%t Log[ 1+Tan[ x ]*Cosh[ x ]]

%t CoefficientList[Series[Log[1 + Cosh[x]*Tan[x]], {x, 0, 20}], x] * Range[0, 20]! (* _Vaclav Kotesovec_, Jan 24 2015 *)

%K sign,easy

%O 0,4

%A _R. H. Hardin_

%E Extended with signs by _Olivier GĂ©rard_, Mar 15 1997

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 19 22:34 EDT 2024. Contains 374441 sequences. (Running on oeis4.)