A058165 Number of labeled lattices with a fixed bottom and top.

1, 1, 3, 19, 213, 3761, 96373, 3377487, 154874569, 8980530625, 641008120761, 55110586506119, 5606337607922197, 664893010179107529, 90785224148218811149, 14119839142088335522351, 2478547355267024762146257

Offset: 2

Author

Christian G. Bower, Nov 15 2000

Keywords

• nonn
• hard
• more

Crossrefs

Cf. A055512, A058164.

Programs

Mathematica

A055512 = Cases[Import["https://oeis.org/A055512/b055512.txt", "Table"], {, }][[All, 2]];
a[n_] := A055512[[n+1]]/(n(n-1));
a /@ Range[2, 18] (* Jean-François Alcover, Jan 02 2020 *)

Formula

a(n) = A055512(n)/(n*(n-1)) = A058164(n)/(n-1).

Extensions

a(18) from Jean-François Alcover, Jan 02 2020