A370708 - cp's OEIS frontend

A370708 a(1)=1; thereafter a(n) is the smallest number > a(n-1) such that no two triples of earlier terms in arithmetic progression have the same common difference.

n	a(n)
1	1
2	2
3	3
4	5
5	6
6	8
7	12
8	13
9	15
10	16
11	21
12	23
13	28
14	32
15	37
16	38
17	40
18	45
19	47
20	61
21	63
22	70
23	73
24	80
25	81
26	91
27	96
28	100
29	103
30	105
31	116
32	123
33	128
34	134
35	138
36	150
37	156
38	157
39	175
40	179
41	181
42	190
43	207
44	210
45	214
46	217
47	226
48	240
49	243
50	252
51	256
52	265
53	275
54	281
55	283
56	289
57	292
58	293
59	308
60	315

[1, 2, 3, 5, 6, 8, 12, 13, 15, 16, 21, 23, 28, 32, 37, 38, 40, 45, 47, 61, 63, 70, 73, 80, 81, 91, 96, 100, 103, 105, 116, 123, 128, 134, 138, 150, 156, 157, 175, 179, 181, 190, 207, 210, 214, 217, 226, 240, 243, 252, 256, 265, 275, 281, 283, 289, 292, 293, 308, 315]

cp's OEIS Frontend

A370708 a(1)=1; thereafter a(n) is the smallest number > a(n-1) such that no two triples of earlier terms in arithmetic progression have the same common difference.

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	5
5	6
6	8
7	12
8	13
9	15
10	16
11	21
12	23
13	28
14	32
15	37
16	38
17	40
18	45
19	47
20	61
21	63
22	70
23	73
24	80
25	81
26	91
27	96
28	100
29	103
30	105
31	116
32	123
33	128
34	134
35	138
36	150
37	156
38	157
39	175
40	179
41	181
42	190
43	207
44	210
45	214
46	217
47	226
48	240
49	243
50	252
51	256
52	265
53	275
54	281
55	283
56	289
57	292
58	293
59	308
60	315

n	a(n)
1	1
2	2
3	3
4	5
5	6
6	8
7	12
8	13
9	15
10	16
11	21
12	23
13	28
14	32
15	37
16	38
17	40
18	45
19	47
20	61
21	63
22	70
23	73
24	80
25	81
26	91
27	96
28	100
29	103
30	105
31	116
32	123
33	128
34	134
35	138
36	150
37	156
38	157
39	175
40	179
41	181
42	190
43	207
44	210
45	214
46	217
47	226
48	240
49	243
50	252
51	256
52	265
53	275
54	281
55	283
56	289
57	292
58	293
59	308
60	315

n	a(n)
1	1
2	2
3	3
4	5
5	6
6	8
7	12
8	13
9	15
10	16
11	21
12	23
13	28
14	32
15	37
16	38
17	40
18	45
19	47
20	61
21	63
22	70
23	73
24	80
25	81
26	91
27	96
28	100
29	103
30	105
31	116
32	123
33	128
34	134
35	138
36	150
37	156
38	157
39	175
40	179
41	181
42	190
43	207
44	210
45	214
46	217
47	226
48	240
49	243
50	252
51	256
52	265
53	275
54	281
55	283
56	289
57	292
58	293
59	308
60	315