A162982 - cp's OEIS frontend

A162982 Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k 3-term arithmetic progressions (n>=0; 0<=k<=floor((n-1)^2/4)).

n	a(n)
0	1
1	1
2	2
3	4
4	2
5	10
6	12
7	2
8	20
9	48
10	46
11	4
12	2
13	48
14	156
15	318
16	152
17	40
18	4
19	2
20	104
21	460
22	1112
23	1690
24	1152
25	406
26	92
27	18
28	4
29	2
30	282
31	1248
32	4058
33	8784
34	11648
35	8856
36	3906
37	1188
38	244
39	80
40	20
41	4
42	2
43	496
44	2924
45	11360
46	31776
47	64020
48	86676
49	80700
50	52800
51	22212
52	6948
53	2158
54	516
55	214
56	52
57	22
58	4
59	2

[1, 1, 2, 4, 2, 10, 12, 2, 20, 48, 46, 4, 2, 48, 156, 318, 152, 40, 4, 2, 104, 460, 1112, 1690, 1152, 406, 92, 18, 4, 2, 282, 1248, 4058, 8784, 11648, 8856, 3906, 1188, 244, 80, 20, 4, 2, 496, 2924, 11360, 31776, 64020, 86676, 80700, 52800, 22212, 6948, 2158, 516, 214, 52, 22, 4, 2]

cp's OEIS Frontend

A162982 Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k 3-term arithmetic progressions (n>=0; 0<=k<=floor((n-1)^2/4)).

Table of values

List of values