A004793 - cp's OEIS frontend

A004793 a(1)=1, a(2)=3; a(n) is least k such that no three terms of a(1), a(2), ..., a(n-1), k form an arithmetic progression.

n	a(n)
1	1
2	3
3	4
4	6
5	10
6	12
7	13
8	15
9	28
10	30
11	31
12	33
13	37
14	39
15	40
16	42
17	82
18	84
19	85
20	87
21	91
22	93
23	94
24	96
25	109
26	111
27	112
28	114
29	118
30	120
31	121
32	123
33	244
34	246
35	247
36	249
37	253
38	255
39	256
40	258
41	271
42	273
43	274
44	276
45	280
46	282
47	283
48	285
49	325
50	327
51	328
52	330
53	334
54	336
55	337
56	339
57	352
58	354

[1, 3, 4, 6, 10, 12, 13, 15, 28, 30, 31, 33, 37, 39, 40, 42, 82, 84, 85, 87, 91, 93, 94, 96, 109, 111, 112, 114, 118, 120, 121, 123, 244, 246, 247, 249, 253, 255, 256, 258, 271, 273, 274, 276, 280, 282, 283, 285, 325, 327, 328, 330, 334, 336, 337, 339, 352, 354]

cp's OEIS Frontend

A004793 a(1)=1, a(2)=3; a(n) is least k such that no three terms of a(1), a(2), ..., a(n-1), k form an arithmetic progression.

Table of values

List of values

n	a(n)
1	1
2	3
3	4
4	6
5	10
6	12
7	13
8	15
9	28
10	30
11	31
12	33
13	37
14	39
15	40
16	42
17	82
18	84
19	85
20	87
21	91
22	93
23	94
24	96
25	109
26	111
27	112
28	114
29	118
30	120
31	121
32	123
33	244
34	246
35	247
36	249
37	253
38	255
39	256
40	258
41	271
42	273
43	274
44	276
45	280
46	282
47	283
48	285
49	325
50	327
51	328
52	330
53	334
54	336
55	337
56	339
57	352
58	354

n	a(n)
1	1
2	3
3	4
4	6
5	10
6	12
7	13
8	15
9	28
10	30
11	31
12	33
13	37
14	39
15	40
16	42
17	82
18	84
19	85
20	87
21	91
22	93
23	94
24	96
25	109
26	111
27	112
28	114
29	118
30	120
31	121
32	123
33	244
34	246
35	247
36	249
37	253
38	255
39	256
40	258
41	271
42	273
43	274
44	276
45	280
46	282
47	283
48	285
49	325
50	327
51	328
52	330
53	334
54	336
55	337
56	339
57	352
58	354

n	a(n)
1	1
2	3
3	4
4	6
5	10
6	12
7	13
8	15
9	28
10	30
11	31
12	33
13	37
14	39
15	40
16	42
17	82
18	84
19	85
20	87
21	91
22	93
23	94
24	96
25	109
26	111
27	112
28	114
29	118
30	120
31	121
32	123
33	244
34	246
35	247
36	249
37	253
38	255
39	256
40	258
41	271
42	273
43	274
44	276
45	280
46	282
47	283
48	285
49	325
50	327
51	328
52	330
53	334
54	336
55	337
56	339
57	352
58	354