A112311 a(1)=1, a(2)=2, a(3)=9; a(n) = n*(n - 2)*a(n - 1)^2/(n - 1).

1, 2, 9, 216, 174960, 146932807680, 125937291507579224064000, 108755666689817047890109782510255885778944000000, 93143885917529328515023382841413836868525118214478405334515136630707122998865821696000000000000

Offset

1,2

Comments

Lower bound to number of perfect Morse matchings of n-simplex.

References

M. K. Chari and M. Joswig, Complexes of discrete Morse functions, Disc. Math. 302 (2005), 39-51.

Links

Table of n, a(n) for n=1..9.

Crossrefs

Cf. A005271.

Sequence in context: A111832 A114563 A217017 * A067564 A267408 A359608

Adjacent sequences: A112308 A112309 A112310 * A112312 A112313 A112314

Keyword

nonn

Author

N. J. A. Sloane, Dec 01 2005

Status

approved