A062781 - cp's OEIS frontend

A062781 Number of arithmetic progressions of four terms and any mean which can be extracted from the set of the first n positive integers.

n	a(n)
1	0
2	0
3	0
4	1
5	2
6	3
7	5
8	7
9	9
10	12
11	15
12	18
13	22
14	26
15	30
16	35
17	40
18	45
19	51
20	57
21	63
22	70
23	77
24	84
25	92
26	100
27	108
28	117
29	126
30	135
31	145
32	155
33	165
34	176
35	187
36	198
37	210
38	222
39	234
40	247
41	260
42	273
43	287
44	301
45	315
46	330
47	345
48	360
49	376
50	392

[0, 0, 0, 1, 2, 3, 5, 7, 9, 12, 15, 18, 22, 26, 30, 35, 40, 45, 51, 57, 63, 70, 77, 84, 92, 100, 108, 117, 126, 135, 145, 155, 165, 176, 187, 198, 210, 222, 234, 247, 260, 273, 287, 301, 315, 330, 345, 360, 376, 392]

cp's OEIS Frontend

A062781 Number of arithmetic progressions of four terms and any mean which can be extracted from the set of the first n positive integers.

Table of values

List of values

n	a(n)
1	0
2	0
3	0
4	1
5	2
6	3
7	5
8	7
9	9
10	12
11	15
12	18
13	22
14	26
15	30
16	35
17	40
18	45
19	51
20	57
21	63
22	70
23	77
24	84
25	92
26	100
27	108
28	117
29	126
30	135
31	145
32	155
33	165
34	176
35	187
36	198
37	210
38	222
39	234
40	247
41	260
42	273
43	287
44	301
45	315
46	330
47	345
48	360
49	376
50	392

n	a(n)
1	0
2	0
3	0
4	1
5	2
6	3
7	5
8	7
9	9
10	12
11	15
12	18
13	22
14	26
15	30
16	35
17	40
18	45
19	51
20	57
21	63
22	70
23	77
24	84
25	92
26	100
27	108
28	117
29	126
30	135
31	145
32	155
33	165
34	176
35	187
36	198
37	210
38	222
39	234
40	247
41	260
42	273
43	287
44	301
45	315
46	330
47	345
48	360
49	376
50	392

n	a(n)
1	0
2	0
3	0
4	1
5	2
6	3
7	5
8	7
9	9
10	12
11	15
12	18
13	22
14	26
15	30
16	35
17	40
18	45
19	51
20	57
21	63
22	70
23	77
24	84
25	92
26	100
27	108
28	117
29	126
30	135
31	145
32	155
33	165
34	176
35	187
36	198
37	210
38	222
39	234
40	247
41	260
42	273
43	287
44	301
45	315
46	330
47	345
48	360
49	376
50	392