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

1,4

Links

Table of n, a(n) for n=1..34.

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

Crossrefs

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

Sequence in context: A177794 A004149 A129986 * A317880 A299271 A110334

Adjacent sequences: A368458 A368459 A368460 * A368462 A368463 A368464

Keyword

nonn

Author

Jukka Kohonen, Dec 25 2023

Status

approved