A277661 1st-order coefficients of the 1/N-expansion of traces of negative powers of real Wishart matrices with parameter c=2.

0, 0, 2, 18, 128, 840, 5306, 32802, 200064, 1209168, 7261042, 43394802, 258401216, 1534310232, 9089538922, 53748310338, 317337926144, 1871206403232, 11021718519266, 64859423566290, 381371547195648, 2240888478928488, 13159108981577242, 77232197285953890, 453066998085075840, 2656691258873376240

Offset

0,3

Comments

These numbers provide the 1st 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.)

Links

G. C. Greubel, Table of n, a(n) for n = 0..1000

F. D. Cunden, F. Mezzadri, N. Simm and P. Vivo, Large-N expansion for the time-delay matrix of ballistic chaotic cavities, J. Math. Phys. 57, 111901 (2016).

J. Kuipers, M. Sieber and D. Savin, Efficient semiclassical approach for time delays, New J. Phys. 16 (2014), 123018.

Formula

G.f.: (1-3*x)/(2*(x^2-6*x+1))-1/(2*(x^2-6*x+1)^(1/2)).

a(n) ~ 2^(-5/2) * (3*sqrt(2)-4) * (1+sqrt(2))^(2*n+2) * (1 - 1/(sqrt(Pi*(3*sqrt(2)-4)*n))). - Vaclav Kotesovec, Oct 27 2016

Mathematica

CoefficientList[Series[(1 - 3 x)/(2 (x^2 - 6 x + 1)) - 1/(2 (x^2 - 6 x + 1)^(1/2)), {x, 0, 25}], x] (* Michael De Vlieger, Oct 26 2016 *)

Crossrefs

Cf. A006318 (0th order), A277662 (2nd order), A277663 (3rd order), A277664 (4th order), A277665 (5th order).

Sequence in context: A358952 A060589 A325275 * A367553 A363662 A064447

Adjacent sequences: A277658 A277659 A277660 * A277662 A277663 A277664

Keyword

nonn

Author

Fabio Deelan Cunden, Oct 26 2016

Extensions

More terms from Michael De Vlieger, Oct 26 2016

Status

approved