login
Number of connected vertically indecomposable partial lattices on n unlabeled nodes.
0

%I #13 Mar 17 2020 19:31:40

%S 1,2,6,25,116,625,3757,25140,184511,1473861,12711339,117598686,

%T 1160399052,12152333659,134487937252,1566878426731,19154490559458

%N Number of connected vertically indecomposable partial lattices on n unlabeled nodes.

%C A partial lattice is a poset where every pair of points has a unique least upper (greatest lower) bound or has no upper (lower) bound.

%H N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>

%F Inverse EULER transform of A058800(n+2).

%t A058800 = Cases[Import["https://oeis.org/A058800/b058800.txt", "Table"], {_, _}][[All, 2]];

%t (* EulerInvTransform is defined in A022562 *)

%t EulerInvTransform[Drop[A058800, 3]] // Rest (* _Jean-François Alcover_, May 10 2019, updated Mar 17 2020 *)

%Y Cf. A006966.

%K nonn,hard

%O 2,2

%A _Christian G. Bower_, Dec 28 2000

%E a(17)-a(18) (computed from A058800) from _Jean-François Alcover_, May 10 2019