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!)
A277663 3rd-order coefficients of the 1/N-expansion of traces of negative powers of real Wishart matrices with parameter c=2. 6

%I #32 Feb 01 2021 02:06:08

%S 0,0,10,378,7048,96000,1092460,11060700,103150528,905077728,

%T 7576640950,61098854454,477942694136,3645484792560,27220292840440,

%U 199588002587160,1440630859132416,10256896070590464,72150109176698562,502120765832371602,3461203073248719400,23654601049848668256

%N 3rd-order coefficients of the 1/N-expansion of traces of negative powers of real Wishart matrices with parameter c=2.

%C These numbers provide the 3rd order of the 1/N-expansion of traces of powers of a random time-delay matrix in presence of time-reversal symmetry. (The 0th order is given by the Large Schröder numbers A006318.)

%H G. C. Greubel, <a href="/A277663/b277663.txt">Table of n, a(n) for n = 0..1000</a>

%H F. D. Cunden, F. Mezzadri, N. Simm and P. Vivo, <a href="http://arxiv.org/abs/1607.00250">Large-N expansion for the time-delay matrix of ballistic chaotic cavities</a>, J. Math. Phys. 57, 111901 (2016). E-print arXiv:1607.00250.

%H J. Kuipers, M. Sieber and D. Savin, <a href="http://arxiv.org/abs/1409.1532">Efficient semiclassical approach for time delays</a>, New J. Phys. 16, 123018 (2014), arXiv:1409.1532 [nlin.CD], 2014.

%F G.f.: -(2*z)*(2*z^3-9*z^2+19*z+3)/(y(z)^(7/2))-(2*z)*(6*z^4-5*z^3+9*z^2-15*z-3)/(y(z)^4) where y(z)=z^2-6*z+1.

%F a(n) ~ (17*sqrt(2)/24-1) * n^3 * (1+sqrt(2))^(2*n+6) * (1 - (7*sqrt((8+6*sqrt(2)) / Pi))/(8*sqrt(n))). - _Vaclav Kotesovec_, Oct 27 2016

%t CoefficientList[Series[-(2 x) (2 x^3 - 9 x^2 + 19 x + 3) / ((x^2 - 6 x + 1)^(7/2)) - (2 x) (6 x^4 - 5 x^3 + 9 x^2 - 15 x - 3) / ((x^2 - 6 x + 1)^4), {x, 0, 25}], x] (* _Vincenzo Librandi_, Nov 07 2016 *)

%Y Cf. A006318 (0th order), A277661 (1st order), A277662 (2nd order), A277664 (4th order), A277665 (5th order).

%K nonn

%O 0,3

%A _Fabio Deelan Cunden_, Oct 26 2016

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 April 25 01:35 EDT 2024. Contains 371964 sequences. (Running on oeis4.)