A281547 - cp's OEIS frontend

A281547 Total number of subsets of X that are both open and closed summed over all distinct topological spaces X that can be placed on an n-set.

n	a(n)
0	1
1	2
2	10
3	82
4	1038
5	19754
6	561778
7	23890766
8	1516425978
9	142478603490
10	19560464078774
11	3868751287074546
12	1088233853378616578
13	430599111941369628326
14	237480490462200909980594
15	181131722604060126010422898
16	189780362331001773747253412782
17	271553393666987988551182068682458
18	527932854364810523962111033565618786

[1, 2, 10, 82, 1038, 19754, 561778, 23890766, 1516425978, 142478603490, 19560464078774, 3868751287074546, 1088233853378616578, 430599111941369628326, 237480490462200909980594, 181131722604060126010422898, 189780362331001773747253412782, 271553393666987988551182068682458, 527932854364810523962111033565618786]

cp's OEIS Frontend

A281547 Total number of subsets of X that are both open and closed summed over all distinct topological spaces X that can be placed on an n-set.

Table of values

List of values