A368461 a(n) is the number of unlabeled planar modular lattices on n nodes.

1, 1, 1, 2, 4, 8, 16, 33, 70, 151, 329, 723, 1601, 3569, 8000, 18015, 40723, 92351, 209997, 478598, 1092856, 2499567, 5724970, 13128115, 30135636, 69238343, 159202607, 366308948, 843338278, 1942591448, 4476714720, 10320774953, 23802355725, 54911686727

Offset: 1

Author

Jukka Kohonen, Dec 25 2023

Keywords

• nonn

Links

• Jukka Kohonen, Modular racks (code to compute the numbers).

Crossrefs

Cf. A006981 (modular lattices), A343161 (planar distributive lattices).