A105748 - cp's OEIS frontend

A105748 Number of ways to use the elements of {1,..,k}, 0<=k<=2n, once each to form a collection of n (possibly empty) sets, each with at most 2 elements.

n	a(n)
0	1
1	3
2	10
3	47
4	313
5	2744
6	29751
7	383273
8	5713110
9	96673861
10	1830257967
11	38326484944
12	879473289521
13	21944639630923
14	591545277653354
15	17131028946645255
16	530424623323416617
17	17485652721425863464
18	611431929749388274471
19	22604399407882099928577

[1, 3, 10, 47, 313, 2744, 29751, 383273, 5713110, 96673861, 1830257967, 38326484944, 879473289521, 21944639630923, 591545277653354, 17131028946645255, 530424623323416617, 17485652721425863464, 611431929749388274471, 22604399407882099928577]

cp's OEIS Frontend

A105748 Number of ways to use the elements of {1,..,k}, 0<=k<=2n, once each to form a collection of n (possibly empty) sets, each with at most 2 elements.

Table of values

List of values