A351823 - cp's OEIS frontend

A351823 Triangular array read by rows. T(n,k) is the number of sets of lists (as in A000262(n)) with exactly k size 2 lists, n >= 0, 0 <= k <= floor(n/2).

n	a(n)
0	1
1	1
2	1
3	2
4	7
5	6
6	49
7	12
8	12
9	301
10	140
11	60
12	2281
13	1470
14	180
15	120
16	21211
17	12642
18	2940
19	840
20	220417
21	127736
22	41160
23	3360
24	1680
25	2528569
26	1527192
27	455112
28	70560
29	15120
30	32014801
31	19837530
32	5748120
33	1234800
34	75600
35	30240
36	442974511
37	278142590
38	83995560
39	16687440
40	1940400
41	332640

[1, 1, 1, 2, 7, 6, 49, 12, 12, 301, 140, 60, 2281, 1470, 180, 120, 21211, 12642, 2940, 840, 220417, 127736, 41160, 3360, 1680, 2528569, 1527192, 455112, 70560, 15120, 32014801, 19837530, 5748120, 1234800, 75600, 30240, 442974511, 278142590, 83995560, 16687440, 1940400, 332640]

cp's OEIS Frontend

A351823 Triangular array read by rows. T(n,k) is the number of sets of lists (as in A000262(n)) with exactly k size 2 lists, n >= 0, 0 <= k <= floor(n/2).

Table of values

List of values