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!)
A009411 Expansion of log(1+x)*cosh(log(1+x)). 1

%I #22 Jun 24 2015 04:35:38

%S 0,1,-1,5,-24,134,-870,6474,-54432,510768,-5294160,60090480,

%T -741407040,9881421120,-141493322880,2166467990400,-35323552051200,

%U 611048958105600,-11178032634316800,215604729694771200,-4373272831527936000

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

%C |a(n)| = number of cycles in all permutations of [n] with odd number of cycles. - _Vladeta Jovovic_, Sep 06 2007

%C a(n) is a function of the harmonic numbers. - _Gary Detlefs_, Jul 13 2010

%H Robert Israel, <a href="/A009411/b009411.txt">Table of n, a(n) for n = 0..411</a>

%F a(n) = (-1)^(n+1)/2*(n!*H(n)-(n-2)!), n> 1, where H(n) = sum(1/k, k=1..n). - _Gary Detlefs_, Jul 13 2010

%p H:= n-> sum(1/k,k=1..n): seq((-1)^(n+1)/2*(n!*H(n)-(n-2)!),n = 2..20); # _Gary Detlefs_, Jul 13 2010

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

%Y Cf. A000254.

%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 September 1 14:13 EDT 2024. Contains 375591 sequences. (Running on oeis4.)