A340107 - cp's OEIS frontend

A340107 Triangle read by rows: T(n,k) is the number of permutations of k elements from [1..n] with longest consecutive chain size less than 3, when 1 and n are considered to be consecutive.

n	a(n)
0	1
1	1
2	1
3	1
4	2
5	2
6	1
7	3
8	6
9	0
10	1
11	4
12	12
13	16
14	16
15	1
16	5
17	20
18	50
19	90
20	80
21	1
22	6
23	30
24	108
25	300
26	552
27	516
28	1
29	7
30	42
31	196
32	742
33	2100
34	3990
35	3794
36	1
37	8
38	56
39	320
40	1536
41	5888
42	16976
43	32656
44	31456
45	1
46	9
47	72
48	486
49	2826
50	13680
51	53046
52	154350
53	299628
54	290970
55	1
56	10
57	90
58	700
59	4780
60	27960
61	136380
62	532340
63	1559040
64	3044900
65	2974380

[1, 1, 1, 1, 2, 2, 1, 3, 6, 0, 1, 4, 12, 16, 16, 1, 5, 20, 50, 90, 80, 1, 6, 30, 108, 300, 552, 516, 1, 7, 42, 196, 742, 2100, 3990, 3794, 1, 8, 56, 320, 1536, 5888, 16976, 32656, 31456, 1, 9, 72, 486, 2826, 13680, 53046, 154350, 299628, 290970, 1, 10, 90, 700, 4780, 27960, 136380, 532340, 1559040, 3044900, 2974380]

cp's OEIS Frontend

A340107 Triangle read by rows: T(n,k) is the number of permutations of k elements from [1..n] with longest consecutive chain size less than 3, when 1 and n are considered to be consecutive.

Table of values

List of values