A058790 - cp's OEIS frontend

A058790 Number of covers of an unlabeled n-set such that every point of the set is covered by exactly 3 subsets of the cover and that intersection of every 3 subsets of the cover contains at most one point.

n	a(n)
1	1
2	3
3	12
4	66
5	445
6	4279
7	53340
8	846254
9	16333946
10	371976963
11	9763321109
12	290473143807
13	9674133467729
14	357177322891321
15	14503958827502886
16	643502334799711633
17	31018731336031551119
18	1616523352051185316626
19	90689288905913623412837
20	5456178840303106057314759
21	350830170593891706361540379

[1, 3, 12, 66, 445, 4279, 53340, 846254, 16333946, 371976963, 9763321109, 290473143807, 9674133467729, 357177322891321, 14503958827502886, 643502334799711633, 31018731336031551119, 1616523352051185316626, 90689288905913623412837, 5456178840303106057314759, 350830170593891706361540379]

cp's OEIS Frontend

A058790 Number of covers of an unlabeled n-set such that every point of the set is covered by exactly 3 subsets of the cover and that intersection of every 3 subsets of the cover contains at most one point.

Table of values

List of values