A213211 - cp's OEIS frontend

A213211 Triangular array read by rows: T(n,k) is the number of size k subsets of {1,2,...,n} such that (when the elements are arranged in increasing order) the smallest element is congruent to 1 mod 3 and the difference of every pair of successive elements is also congruent to 1 mod 3.

n	a(n)
0	1
1	1
2	1
3	1
4	1
5	1
6	1
7	1
8	1
9	1
10	1
11	2
12	1
13	1
14	1
15	1
16	2
17	3
18	1
19	1
20	1
21	1
22	2
23	3
24	4
25	1
26	1
27	1
28	1
29	3
30	3
31	4
32	5
33	1
34	1
35	1
36	1
37	3
38	6
39	4
40	5
41	6
42	1
43	1
44	1
45	1
46	3
47	6
48	10
49	5
50	6
51	7
52	1
53	1
54	1
55	1
56	4
57	6
58	10
59	15
60	6
61	7
62	8
63	1
64	1
65	1
66	1
67	4
68	10
69	10
70	15
71	21
72	7
73	8
74	9
75	1
76	1
77	1
78	1
79	4
80	10
81	20
82	15
83	21
84	28
85	8
86	9
87	10
88	1
89	1
90	1

[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 3, 1, 1, 1, 1, 2, 3, 4, 1, 1, 1, 1, 3, 3, 4, 5, 1, 1, 1, 1, 3, 6, 4, 5, 6, 1, 1, 1, 1, 3, 6, 10, 5, 6, 7, 1, 1, 1, 1, 4, 6, 10, 15, 6, 7, 8, 1, 1, 1, 1, 4, 10, 10, 15, 21, 7, 8, 9, 1, 1, 1, 1, 4, 10, 20, 15, 21, 28, 8, 9, 10, 1, 1, 1]

cp's OEIS Frontend

A213211 Triangular array read by rows: T(n,k) is the number of size k subsets of {1,2,...,n} such that (when the elements are arranged in increasing order) the smallest element is congruent to 1 mod 3 and the difference of every pair of successive elements is also congruent to 1 mod 3.

Table of values

List of values

n	a(n)
0	1
1	1
2	1
3	1
4	1
5	1
6	1
7	1
8	1
9	1
10	1
11	2
12	1
13	1
14	1
15	1
16	2
17	3
18	1
19	1
20	1
21	1
22	2
23	3
24	4
25	1
26	1
27	1
28	1
29	3
30	3
31	4
32	5
33	1
34	1
35	1
36	1
37	3
38	6
39	4
40	5
41	6
42	1
43	1
44	1
45	1
46	3
47	6
48	10
49	5
50	6
51	7
52	1
53	1
54	1
55	1
56	4
57	6
58	10
59	15
60	6
61	7
62	8
63	1
64	1
65	1
66	1
67	4
68	10
69	10
70	15
71	21
72	7
73	8
74	9
75	1
76	1
77	1
78	1
79	4
80	10
81	20
82	15
83	21
84	28
85	8
86	9
87	10
88	1
89	1
90	1

n	a(n)
0	1
1	1
2	1
3	1
4	1
5	1
6	1
7	1
8	1
9	1
10	1
11	2
12	1
13	1
14	1
15	1
16	2
17	3
18	1
19	1
20	1
21	1
22	2
23	3
24	4
25	1
26	1
27	1
28	1
29	3
30	3
31	4
32	5
33	1
34	1
35	1
36	1
37	3
38	6
39	4
40	5
41	6
42	1
43	1
44	1
45	1
46	3
47	6
48	10
49	5
50	6
51	7
52	1
53	1
54	1
55	1
56	4
57	6
58	10
59	15
60	6
61	7
62	8
63	1
64	1
65	1
66	1
67	4
68	10
69	10
70	15
71	21
72	7
73	8
74	9
75	1
76	1
77	1
78	1
79	4
80	10
81	20
82	15
83	21
84	28
85	8
86	9
87	10
88	1
89	1
90	1

n	a(n)
0	1
1	1
2	1
3	1
4	1
5	1
6	1
7	1
8	1
9	1
10	1
11	2
12	1
13	1
14	1
15	1
16	2
17	3
18	1
19	1
20	1
21	1
22	2
23	3
24	4
25	1
26	1
27	1
28	1
29	3
30	3
31	4
32	5
33	1
34	1
35	1
36	1
37	3
38	6
39	4
40	5
41	6
42	1
43	1
44	1
45	1
46	3
47	6
48	10
49	5
50	6
51	7
52	1
53	1
54	1
55	1
56	4
57	6
58	10
59	15
60	6
61	7
62	8
63	1
64	1
65	1
66	1
67	4
68	10
69	10
70	15
71	21
72	7
73	8
74	9
75	1
76	1
77	1
78	1
79	4
80	10
81	20
82	15
83	21
84	28
85	8
86	9
87	10
88	1
89	1
90	1