A026670 - cp's OEIS frontend

A026670 Triangular array T read by rows: T(n,0) = T(n,n) = 1 for n >= 0; for n >= 1, T(n,1) = T(n,n-1) = n+1; for n >= 2, T(n,k) = T(n-1,k-1) + T(n-2,k-1) + T(n-1,k) if n is even and k = n/2, else T(n,k) = T(n-1,k-1) + T(n-1,k).

n	a(n)
0	1
1	1
2	1
3	1
4	3
5	1
6	1
7	4
8	4
9	1
10	1
11	5
12	11
13	5
14	1
15	1
16	6
17	16
18	16
19	6
20	1
21	1
22	7
23	22
24	43
25	22
26	7
27	1
28	1
29	8
30	29
31	65
32	65
33	29
34	8
35	1
36	1
37	9
38	37
39	94
40	173
41	94
42	37
43	9
44	1
45	1
46	10
47	46
48	131
49	267
50	267
51	131
52	46
53	10
54	1
55	1
56	11
57	56
58	177
59	398
60	707
61	398
62	177
63	56
64	11
65	1
66	1
67	12
68	67

[1, 1, 1, 1, 3, 1, 1, 4, 4, 1, 1, 5, 11, 5, 1, 1, 6, 16, 16, 6, 1, 1, 7, 22, 43, 22, 7, 1, 1, 8, 29, 65, 65, 29, 8, 1, 1, 9, 37, 94, 173, 94, 37, 9, 1, 1, 10, 46, 131, 267, 267, 131, 46, 10, 1, 1, 11, 56, 177, 398, 707, 398, 177, 56, 11, 1, 1, 12, 67]

cp's OEIS Frontend

A026670 Triangular array T read by rows: T(n,0) = T(n,n) = 1 for n >= 0; for n >= 1, T(n,1) = T(n,n-1) = n+1; for n >= 2, T(n,k) = T(n-1,k-1) + T(n-2,k-1) + T(n-1,k) if n is even and k = n/2, else T(n,k) = T(n-1,k-1) + T(n-1,k).

Table of values

List of values

n	a(n)
0	1
1	1
2	1
3	1
4	3
5	1
6	1
7	4
8	4
9	1
10	1
11	5
12	11
13	5
14	1
15	1
16	6
17	16
18	16
19	6
20	1
21	1
22	7
23	22
24	43
25	22
26	7
27	1
28	1
29	8
30	29
31	65
32	65
33	29
34	8
35	1
36	1
37	9
38	37
39	94
40	173
41	94
42	37
43	9
44	1
45	1
46	10
47	46
48	131
49	267
50	267
51	131
52	46
53	10
54	1
55	1
56	11
57	56
58	177
59	398
60	707
61	398
62	177
63	56
64	11
65	1
66	1
67	12
68	67

n	a(n)
0	1
1	1
2	1
3	1
4	3
5	1
6	1
7	4
8	4
9	1
10	1
11	5
12	11
13	5
14	1
15	1
16	6
17	16
18	16
19	6
20	1
21	1
22	7
23	22
24	43
25	22
26	7
27	1
28	1
29	8
30	29
31	65
32	65
33	29
34	8
35	1
36	1
37	9
38	37
39	94
40	173
41	94
42	37
43	9
44	1
45	1
46	10
47	46
48	131
49	267
50	267
51	131
52	46
53	10
54	1
55	1
56	11
57	56
58	177
59	398
60	707
61	398
62	177
63	56
64	11
65	1
66	1
67	12
68	67

n	a(n)
0	1
1	1
2	1
3	1
4	3
5	1
6	1
7	4
8	4
9	1
10	1
11	5
12	11
13	5
14	1
15	1
16	6
17	16
18	16
19	6
20	1
21	1
22	7
23	22
24	43
25	22
26	7
27	1
28	1
29	8
30	29
31	65
32	65
33	29
34	8
35	1
36	1
37	9
38	37
39	94
40	173
41	94
42	37
43	9
44	1
45	1
46	10
47	46
48	131
49	267
50	267
51	131
52	46
53	10
54	1
55	1
56	11
57	56
58	177
59	398
60	707
61	398
62	177
63	56
64	11
65	1
66	1
67	12
68	67