A096901 - cp's OEIS frontend

A096901 Number of permutations p of (1,2,3,...,n) such that k+p(k) is a triangular number for 1<=k<=n.

n	a(n)
0	1
1	0
2	1
3	1
4	0
5	1
6	1
7	1
8	2
9	4
10	3
11	9
12	14
13	13
14	52
15	124
16	161
17	181
18	715
19	2338
20	7073
21	8624
22	15466
23	52858
24	150365
25	316543
26	691771
27	1681604
28	5324919
29	15407311
30	37417775
31	69725286
32	155786456
33	579599171
34	2600274145
35	10530031625
36	22971756045
37	47057778714
38	112946192928

[1, 0, 1, 1, 0, 1, 1, 1, 2, 4, 3, 9, 14, 13, 52, 124, 161, 181, 715, 2338, 7073, 8624, 15466, 52858, 150365, 316543, 691771, 1681604, 5324919, 15407311, 37417775, 69725286, 155786456, 579599171, 2600274145, 10530031625, 22971756045, 47057778714, 112946192928]

cp's OEIS Frontend

A096901 Number of permutations p of (1,2,3,...,n) such that k+p(k) is a triangular number for 1<=k<=n.

Table of values

List of values