A060174 Dimensions of graded algebra associated with forest meanders (subalgebra version).

1, 4, 32, 320, 3536, 41344, 501264, 6232736, 78948912, 1014329856, 13178920016, 172789849952, 2282474558160, 30340247738176, 405461900524400, 5443463231234592, 73372619284217776, 992459740253399360, 13465895431077568080, 183211658096891394848, 2498857102607629076880

Offset: 0

Author

N. J. A. Sloane, Apr 10 2001

Keywords

• nonn

Comments

Number of meander slices with 2n crossings which are closed on one side and whose loops are all even. A loop is even if it has its least point at an even index with crossings numbered from zero. - Andrew Howroyd, Feb 07 2025

Links

• Roland Bacher, Meander algebras, Institut Fourier, UMR 5582, Laboratoire de Mathématiques, 1999.

Crossrefs

Meander sequences in Bacher's paper: A005315, A060066, A060089, A060111, A060148, A060149, A060174, A060198, A060206.

Extensions

Offset corrected and a(7) onwards from Andrew Howroyd, Jan 31 2025