A155997 - cp's OEIS frontend

A155997 Triangle read by rows: T(n, k) = f(n, k) + f(n, n-k), where f(n, k) = binomial(n, k)*(1 + (-1)^k)/2.

n	a(n)
0	2
1	1
2	1
3	2
4	0
5	2
6	1
7	3
8	3
9	1
10	2
11	0
12	12
13	0
14	2
15	1
16	5
17	10
18	10
19	5
20	1
21	2
22	0
23	30
24	0
25	30
26	0
27	2
28	1
29	7
30	21
31	35
32	35
33	21
34	7
35	1
36	2
37	0
38	56
39	0
40	140
41	0
42	56
43	0
44	2
45	1
46	9
47	36
48	84
49	126
50	126
51	84
52	36
53	9
54	1
55	2
56	0
57	90
58	0
59	420
60	0
61	420
62	0
63	90
64	0
65	2
66	1
67	11
68	55
69	165
70	330
71	462
72	462
73	330
74	165
75	55
76	11
77	1

[2, 1, 1, 2, 0, 2, 1, 3, 3, 1, 2, 0, 12, 0, 2, 1, 5, 10, 10, 5, 1, 2, 0, 30, 0, 30, 0, 2, 1, 7, 21, 35, 35, 21, 7, 1, 2, 0, 56, 0, 140, 0, 56, 0, 2, 1, 9, 36, 84, 126, 126, 84, 36, 9, 1, 2, 0, 90, 0, 420, 0, 420, 0, 90, 0, 2, 1, 11, 55, 165, 330, 462, 462, 330, 165, 55, 11, 1]

cp's OEIS Frontend

A155997 Triangle read by rows: T(n, k) = f(n, k) + f(n, n-k), where f(n, k) = binomial(n, k)*(1 + (-1)^k)/2.

Table of values

List of values

n	a(n)
0	2
1	1
2	1
3	2
4	0
5	2
6	1
7	3
8	3
9	1
10	2
11	0
12	12
13	0
14	2
15	1
16	5
17	10
18	10
19	5
20	1
21	2
22	0
23	30
24	0
25	30
26	0
27	2
28	1
29	7
30	21
31	35
32	35
33	21
34	7
35	1
36	2
37	0
38	56
39	0
40	140
41	0
42	56
43	0
44	2
45	1
46	9
47	36
48	84
49	126
50	126
51	84
52	36
53	9
54	1
55	2
56	0
57	90
58	0
59	420
60	0
61	420
62	0
63	90
64	0
65	2
66	1
67	11
68	55
69	165
70	330
71	462
72	462
73	330
74	165
75	55
76	11
77	1

n	a(n)
0	2
1	1
2	1
3	2
4	0
5	2
6	1
7	3
8	3
9	1
10	2
11	0
12	12
13	0
14	2
15	1
16	5
17	10
18	10
19	5
20	1
21	2
22	0
23	30
24	0
25	30
26	0
27	2
28	1
29	7
30	21
31	35
32	35
33	21
34	7
35	1
36	2
37	0
38	56
39	0
40	140
41	0
42	56
43	0
44	2
45	1
46	9
47	36
48	84
49	126
50	126
51	84
52	36
53	9
54	1
55	2
56	0
57	90
58	0
59	420
60	0
61	420
62	0
63	90
64	0
65	2
66	1
67	11
68	55
69	165
70	330
71	462
72	462
73	330
74	165
75	55
76	11
77	1

n	a(n)
0	2
1	1
2	1
3	2
4	0
5	2
6	1
7	3
8	3
9	1
10	2
11	0
12	12
13	0
14	2
15	1
16	5
17	10
18	10
19	5
20	1
21	2
22	0
23	30
24	0
25	30
26	0
27	2
28	1
29	7
30	21
31	35
32	35
33	21
34	7
35	1
36	2
37	0
38	56
39	0
40	140
41	0
42	56
43	0
44	2
45	1
46	9
47	36
48	84
49	126
50	126
51	84
52	36
53	9
54	1
55	2
56	0
57	90
58	0
59	420
60	0
61	420
62	0
63	90
64	0
65	2
66	1
67	11
68	55
69	165
70	330
71	462
72	462
73	330
74	165
75	55
76	11
77	1