A380336 - cp's OEIS frontend

A380336 Triangular array read by rows. T(n,k) is the number of ways to choose a size k subset S of [n] and form a labeled acyclic digraph on S. Then form another labeled acyclic digraph on [n]-S. For each pair u in S and v in [n]-S add the directed edge u->v or not, n>=0, 0<=k<=n.

n	a(n)
0	1
1	1
2	1
3	3
4	4
5	3
6	25
7	36
8	36
9	25
10	543
11	800
12	864
13	800
14	543
15	29281
16	43440
17	48000
18	48000
19	43440
20	29281
21	3781503
22	5621952
23	6255360
24	6400000
25	6255360
26	5621952
27	3781503
28	1138779265
29	1694113344
30	1888975872
31	1946112000
32	1946112000
33	1888975872
34	1694113344
35	1138779265

[1, 1, 1, 3, 4, 3, 25, 36, 36, 25, 543, 800, 864, 800, 543, 29281, 43440, 48000, 48000, 43440, 29281, 3781503, 5621952, 6255360, 6400000, 6255360, 5621952, 3781503, 1138779265, 1694113344, 1888975872, 1946112000, 1946112000, 1888975872, 1694113344, 1138779265]

cp's OEIS Frontend

A380336 Triangular array read by rows. T(n,k) is the number of ways to choose a size k subset S of [n] and form a labeled acyclic digraph on S. Then form another labeled acyclic digraph on [n]-S. For each pair u in S and v in [n]-S add the directed edge u->v or not, n>=0, 0<=k<=n.

Table of values

List of values