A143976 - cp's OEIS frontend

A143976 Rectangular array R by antidiagonals: label each unit square in the first quadrant lattice by its northeast vertex (x,y) and mark squares having x + y == 1 (mod 3); then R(m,n) is the number of UNmarked squares in the rectangle [0,m] X [0,n].

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

[1, 2, 2, 2, 3, 2, 3, 4, 4, 3, 4, 6, 6, 6, 4, 4, 7, 8, 8, 7, 4, 5, 8, 10, 11, 10, 8, 5, 6, 10, 12, 14, 14, 12, 10, 6, 6, 11, 14, 16, 17, 16, 14, 11, 6, 7, 12, 16, 19, 20, 20, 19, 16, 12, 7, 8, 14, 18, 22, 24, 24, 24, 22, 18, 14, 8, 8, 15, 20, 24, 27, 28, 28, 27, 24, 20, 15, 8]

cp's OEIS Frontend

A143976 Rectangular array R by antidiagonals: label each unit square in the first quadrant lattice by its northeast vertex (x,y) and mark squares having x + y == 1 (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	1
2	2
3	2
4	2
5	3
6	2
7	3
8	4
9	4
10	3
11	4
12	6
13	6
14	6
15	4
16	4
17	7
18	8
19	8
20	7
21	4
22	5
23	8
24	10
25	11
26	10
27	8
28	5
29	6
30	10
31	12
32	14
33	14
34	12
35	10
36	6
37	6
38	11
39	14
40	16
41	17
42	16
43	14
44	11
45	6
46	7
47	12
48	16
49	19
50	20
51	20
52	19
53	16
54	12
55	7
56	8
57	14
58	18
59	22
60	24
61	24
62	24
63	22
64	18
65	14
66	8
67	8
68	15
69	20
70	24
71	27
72	28
73	28
74	27
75	24
76	20
77	15
78	8

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

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