A144001 - cp's OEIS frontend

A144001 Rectangular array read by antidiagonals: label each unit square in the first quadrant lattice by its northeast vertex (x,y) and mark squares for which x + y == 0 (mod 3); then R(m,n) is the number of unmarked squares in the rectangle [0,m] X [0,n].

n	a(n)
1	0
2	1
3	1
4	1
5	2
6	1
7	1
8	2
9	2
10	1
11	2
12	3
13	3
14	3
15	2
16	2
17	4
18	4
19	4
20	4
21	2
22	2
23	4
24	5
25	5
26	5
27	4
28	2
29	3
30	5
31	6
32	7
33	7
34	6
35	5
36	3
37	3
38	6
39	7
40	8
41	9
42	8
43	7
44	6
45	3
46	3
47	6
48	8
49	9
50	10
51	10
52	9
53	8
54	6
55	3
56	4
57	7
58	9
59	11
60	12
61	12
62	12
63	11
64	9
65	7
66	4
67	4
68	8
69	10
70	12
71	14
72	14
73	14
74	14
75	12
76	10
77	8
78	4
79	4
80	8
81	11
82	13
83	15
84	16
85	16
86	16
87	15
88	13
89	11
90	8
91	4
92	5
93	9

[0, 1, 1, 1, 2, 1, 1, 2, 2, 1, 2, 3, 3, 3, 2, 2, 4, 4, 4, 4, 2, 2, 4, 5, 5, 5, 4, 2, 3, 5, 6, 7, 7, 6, 5, 3, 3, 6, 7, 8, 9, 8, 7, 6, 3, 3, 6, 8, 9, 10, 10, 9, 8, 6, 3, 4, 7, 9, 11, 12, 12, 12, 11, 9, 7, 4, 4, 8, 10, 12, 14, 14, 14, 14, 12, 10, 8, 4, 4, 8, 11, 13, 15, 16, 16, 16, 15, 13, 11, 8, 4, 5, 9]

cp's OEIS Frontend

A144001 Rectangular array read by antidiagonals: label each unit square in the first quadrant lattice by its northeast vertex (x,y) and mark squares for which x + y == 0 (mod 3); then R(m,n) is the number of unmarked squares in the rectangle [0,m] X [0,n].

Table of values

List of values

n	a(n)
1	0
2	1
3	1
4	1
5	2
6	1
7	1
8	2
9	2
10	1
11	2
12	3
13	3
14	3
15	2
16	2
17	4
18	4
19	4
20	4
21	2
22	2
23	4
24	5
25	5
26	5
27	4
28	2
29	3
30	5
31	6
32	7
33	7
34	6
35	5
36	3
37	3
38	6
39	7
40	8
41	9
42	8
43	7
44	6
45	3
46	3
47	6
48	8
49	9
50	10
51	10
52	9
53	8
54	6
55	3
56	4
57	7
58	9
59	11
60	12
61	12
62	12
63	11
64	9
65	7
66	4
67	4
68	8
69	10
70	12
71	14
72	14
73	14
74	14
75	12
76	10
77	8
78	4
79	4
80	8
81	11
82	13
83	15
84	16
85	16
86	16
87	15
88	13
89	11
90	8
91	4
92	5
93	9

n	a(n)
1	0
2	1
3	1
4	1
5	2
6	1
7	1
8	2
9	2
10	1
11	2
12	3
13	3
14	3
15	2
16	2
17	4
18	4
19	4
20	4
21	2
22	2
23	4
24	5
25	5
26	5
27	4
28	2
29	3
30	5
31	6
32	7
33	7
34	6
35	5
36	3
37	3
38	6
39	7
40	8
41	9
42	8
43	7
44	6
45	3
46	3
47	6
48	8
49	9
50	10
51	10
52	9
53	8
54	6
55	3
56	4
57	7
58	9
59	11
60	12
61	12
62	12
63	11
64	9
65	7
66	4
67	4
68	8
69	10
70	12
71	14
72	14
73	14
74	14
75	12
76	10
77	8
78	4
79	4
80	8
81	11
82	13
83	15
84	16
85	16
86	16
87	15
88	13
89	11
90	8
91	4
92	5
93	9

n	a(n)
1	0
2	1
3	1
4	1
5	2
6	1
7	1
8	2
9	2
10	1
11	2
12	3
13	3
14	3
15	2
16	2
17	4
18	4
19	4
20	4
21	2
22	2
23	4
24	5
25	5
26	5
27	4
28	2
29	3
30	5
31	6
32	7
33	7
34	6
35	5
36	3
37	3
38	6
39	7
40	8
41	9
42	8
43	7
44	6
45	3
46	3
47	6
48	8
49	9
50	10
51	10
52	9
53	8
54	6
55	3
56	4
57	7
58	9
59	11
60	12
61	12
62	12
63	11
64	9
65	7
66	4
67	4
68	8
69	10
70	12
71	14
72	14
73	14
74	14
75	12
76	10
77	8
78	4
79	4
80	8
81	11
82	13
83	15
84	16
85	16
86	16
87	15
88	13
89	11
90	8
91	4
92	5
93	9