A026568 - cp's OEIS frontend

A026568 Irregular triangular array T read by rows: T(i,0) = T(i,2i) = 1 for i >= 0; T(i,1) = T(i,2i-1) = [ (i+1)/2 ] for i >= 1; and for i >= 2 and 2 <=j <= i - 2, T(i,j) = T(i-1,j-2) + T(i-1,j-1) + T(i-1,j) if i + j is even, T(i,j) = T(i-1,j-2) + T(i-1,j) if i + j is odd.

n	a(n)
1	1
2	1
3	1
4	1
5	1
6	1
7	3
8	1
9	1
10	1
11	2
12	4
13	5
14	4
15	2
16	1
17	1
18	2
19	7
20	7
21	13
22	7
23	7
24	2
25	1
26	1
27	3
28	8
29	16
30	20
31	27
32	20
33	16
34	8
35	3
36	1
37	1
38	3
39	12
40	19
41	44
42	43
43	67
44	43
45	44
46	19
47	12
48	3
49	1
50	1
51	4
52	13
53	34
54	56
55	106
56	111
57	153
58	111
59	106
60	56
61	34
62	13
63	4
64	1
65	1
66	4
67	18
68	38
69	103
70	140
71	273

[1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 2, 4, 5, 4, 2, 1, 1, 2, 7, 7, 13, 7, 7, 2, 1, 1, 3, 8, 16, 20, 27, 20, 16, 8, 3, 1, 1, 3, 12, 19, 44, 43, 67, 43, 44, 19, 12, 3, 1, 1, 4, 13, 34, 56, 106, 111, 153, 111, 106, 56, 34, 13, 4, 1, 1, 4, 18, 38, 103, 140, 273]

cp's OEIS Frontend

A026568 Irregular triangular array T read by rows: T(i,0) = T(i,2i) = 1 for i >= 0; T(i,1) = T(i,2i-1) = [ (i+1)/2 ] for i >= 1; and for i >= 2 and 2 <=j <= i - 2, T(i,j) = T(i-1,j-2) + T(i-1,j-1) + T(i-1,j) if i + j is even, T(i,j) = T(i-1,j-2) + T(i-1,j) if i + j is odd.

Table of values

List of values

n	a(n)
1	1
2	1
3	1
4	1
5	1
6	1
7	3
8	1
9	1
10	1
11	2
12	4
13	5
14	4
15	2
16	1
17	1
18	2
19	7
20	7
21	13
22	7
23	7
24	2
25	1
26	1
27	3
28	8
29	16
30	20
31	27
32	20
33	16
34	8
35	3
36	1
37	1
38	3
39	12
40	19
41	44
42	43
43	67
44	43
45	44
46	19
47	12
48	3
49	1
50	1
51	4
52	13
53	34
54	56
55	106
56	111
57	153
58	111
59	106
60	56
61	34
62	13
63	4
64	1
65	1
66	4
67	18
68	38
69	103
70	140
71	273

n	a(n)
1	1
2	1
3	1
4	1
5	1
6	1
7	3
8	1
9	1
10	1
11	2
12	4
13	5
14	4
15	2
16	1
17	1
18	2
19	7
20	7
21	13
22	7
23	7
24	2
25	1
26	1
27	3
28	8
29	16
30	20
31	27
32	20
33	16
34	8
35	3
36	1
37	1
38	3
39	12
40	19
41	44
42	43
43	67
44	43
45	44
46	19
47	12
48	3
49	1
50	1
51	4
52	13
53	34
54	56
55	106
56	111
57	153
58	111
59	106
60	56
61	34
62	13
63	4
64	1
65	1
66	4
67	18
68	38
69	103
70	140
71	273

n	a(n)
1	1
2	1
3	1
4	1
5	1
6	1
7	3
8	1
9	1
10	1
11	2
12	4
13	5
14	4
15	2
16	1
17	1
18	2
19	7
20	7
21	13
22	7
23	7
24	2
25	1
26	1
27	3
28	8
29	16
30	20
31	27
32	20
33	16
34	8
35	3
36	1
37	1
38	3
39	12
40	19
41	44
42	43
43	67
44	43
45	44
46	19
47	12
48	3
49	1
50	1
51	4
52	13
53	34
54	56
55	106
56	111
57	153
58	111
59	106
60	56
61	34
62	13
63	4
64	1
65	1
66	4
67	18
68	38
69	103
70	140
71	273