A299296 G.f. 1/(1-z*R(z*m(z))) where R(z) = (1-z-(z+1)*sqrt(1-4*z))/(2*z^2), m(z) = (3-z-sqrt(1-6*z+z^2))/2.

1, 2, 7, 30, 140, 684, 3440, 17652, 91936, 484356, 2575280, 13795668, 74367408, 403026372, 2194186272, 11993494356, 65787201984, 361983246084, 1997299980368, 11048026950228, 61250480822416, 340274092662084, 1893939042807872, 10559753415822420, 58970301517748000

Offset

0,2

Links

Table of n, a(n) for n=0..24.

Michael Anshelevich, Product formulas on posets, Wick products, and a correction for the q-Poisson process, arXiv:1708.08034 [math.OA], 2017.

Maple

R:=z->(1-z-(z+1)*sqrt(1-4*z))/(2*z^2);
m:=z->(3-z-sqrt(1-6*z+z^2))/2;
M:=z->1/(1-z*R(z*m(z)));
series(M(z), z, 40);
seriestolist(%);

Mathematica

R[z_] := (1 - z - (z + 1) Sqrt[1 - 4 z])/(2 z^2); m[z_] := (3 - z - Sqrt[1 - 6 z + z^2])/2; CoefficientList[Series[1/(1 - z R[z m[z]]), {z, 0, 24}], z] (* Michael De Vlieger, Feb 17 2018 *)

Crossrefs

Sequence in context: A375444 A027136 A353288 * A116363 A186858 A360102

Adjacent sequences: A299293 A299294 A299295 * A299297 A299298 A299299

Keyword

nonn

Author

N. J. A. Sloane, Feb 17 2018

Status

approved