A038035 Number of labeled dyslexic planted planar trees with n+1 nodes.

1, 2, 9, 72, 840, 12780, 238770, 5281920, 134946000, 3909578400, 126638542800, 4535037460800, 177904622095200, 7586967310322400, 349479111223242000, 17292052928037888000, 914673660594613920000, 51506610632458293312000, 3076341001739003430432000

Offset: 1

Author

Christian G. Bower, Sep 15 1998

Keywords

• nonn
• eigen

Links

• Andrew Howroyd, Table of n, a(n) for n = 1..200
• C. G. Bower, Transforms (2)
• Index entries for sequences related to rooted trees

Crossrefs

Cf. A005470, A032128.

Programs

Mathematica

m = 20;
CoefficientList[InverseSeries[2*x*(1 - x)/(2 - x^2) + O[x]^m], x]*Range[0, m - 1]! // Rest (* Jean-François Alcover, Sep 08 2019 *)

PARI

Vec(serlaplace(serreverse(2*x*(1 - x)/(2 - x^2) + O(x^20)))) \\ Andrew Howroyd, Sep 19 2018

Formula

Divides by n and shifts left under "BIJ" (reversible, indistinct, labeled) transform.

E.g.f.: series reversion of 2*x*(1 - x)/(2 - x^2). - Andrew Howroyd, Sep 19 2018

Extensions

Terms a(16) and beyond from Andrew Howroyd, Sep 19 2018