A166872 - cp's OEIS frontend

A166872 a(n) = floor(n/2 + 2 - sqrt(17/4 + 2*n)).

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

[0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 2, 3, 3, 3, 3, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 10, 10, 10, 11, 11, 12, 12, 12, 13, 13, 14, 14, 14, 15, 15, 15, 16, 16, 17, 17, 18, 18, 18, 19, 19, 20, 20, 20, 21, 21, 22, 22, 22, 23, 23, 24, 24, 24, 25, 25, 26, 26, 27, 27, 27, 28, 28, 29]

cp's OEIS Frontend

A166872 a(n) = floor(n/2 + 2 - sqrt(17/4 + 2*n)).

Table of values

List of values

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

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

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