A118433 - cp's OEIS frontend

A118433 Self-inverse triangle H, read by rows; a nontrivial matrix square-root of identity: H^2 = I, where H(n,k) = C(n,k)*(-1)^(floor((n+1)/2) - floor(k/2) + n - k) for n >= k >= 0.

n	a(n)
0	1
1	1
2	-1
3	-1
4	2
5	1
6	-1
7	3
8	3
9	-1
10	1
11	-4
12	-6
13	4
14	1
15	1
16	-5
17	-10
18	10
19	5
20	-1
21	-1
22	6
23	15
24	-20
25	-15
26	6
27	1
28	-1
29	7
30	21
31	-35
32	-35
33	21
34	7
35	-1
36	1
37	-8
38	-28
39	56
40	70
41	-56
42	-28
43	8
44	1
45	1
46	-9
47	-36
48	84
49	126
50	-126
51	-84
52	36
53	9
54	-1
55	-1
56	10
57	45
58	-120
59	-210
60	252
61	210
62	-120
63	-45
64	10
65	1

[1, 1, -1, -1, 2, 1, -1, 3, 3, -1, 1, -4, -6, 4, 1, 1, -5, -10, 10, 5, -1, -1, 6, 15, -20, -15, 6, 1, -1, 7, 21, -35, -35, 21, 7, -1, 1, -8, -28, 56, 70, -56, -28, 8, 1, 1, -9, -36, 84, 126, -126, -84, 36, 9, -1, -1, 10, 45, -120, -210, 252, 210, -120, -45, 10, 1]

cp's OEIS Frontend

A118433 Self-inverse triangle H, read by rows; a nontrivial matrix square-root of identity: H^2 = I, where H(n,k) = C(n,k)*(-1)^(floor((n+1)/2) - floor(k/2) + n - k) for n >= k >= 0.

Table of values

List of values