A053156 - cp's OEIS frontend

A053156 Number of 2-element intersecting families (with not necessarily distinct sets) whose union is an n-element set.

n	a(n)
1	1
2	3
3	10
4	33
5	106
6	333
7	1030
8	3153
9	9586
10	29013
11	87550
12	263673
13	793066
14	2383293
15	7158070
16	21490593
17	64504546
18	193579173
19	580868590
20	1742867913
21	5229128026
22	15688432653
23	47067395110
24	141206379633
25	423627527506
26	1270899359733

[1, 3, 10, 33, 106, 333, 1030, 3153, 9586, 29013, 87550, 263673, 793066, 2383293, 7158070, 21490593, 64504546, 193579173, 580868590, 1742867913, 5229128026, 15688432653, 47067395110, 141206379633, 423627527506, 1270899359733]

cp's OEIS Frontend

A053156 Number of 2-element intersecting families (with not necessarily distinct sets) whose union is an n-element set.

Table of values

List of values