A356188 - cp's OEIS frontend

A356188 a(1)=1; for n > 1, if a(n-1) is prime then a(n) = the smallest number not yet in the sequence. Otherwise a(n) = a(n-1) + n - 1.

n	a(n)
1	1
2	2
3	3
4	4
5	8
6	13
7	5
8	6
9	14
10	23
11	7
12	9
13	21
14	34
15	48
16	63
17	79
18	10
19	28
20	47
21	11
22	12
23	34
24	57
25	81
26	106
27	132
28	159
29	187
30	216
31	246
32	277
33	15
34	48
35	82
36	117
37	153
38	190
39	228
40	267
41	307
42	16
43	58
44	101
45	17
46	18
47	64
48	111
49	159
50	208
51	258
52	309
53	361
54	414
55	468
56	523
57	19
58	20
59	78
60	137
61	22
62	83
63	24
64	87
65	151
66	25
67	91

[1, 2, 3, 4, 8, 13, 5, 6, 14, 23, 7, 9, 21, 34, 48, 63, 79, 10, 28, 47, 11, 12, 34, 57, 81, 106, 132, 159, 187, 216, 246, 277, 15, 48, 82, 117, 153, 190, 228, 267, 307, 16, 58, 101, 17, 18, 64, 111, 159, 208, 258, 309, 361, 414, 468, 523, 19, 20, 78, 137, 22, 83, 24, 87, 151, 25, 91]

cp's OEIS Frontend

A356188 a(1)=1; for n > 1, if a(n-1) is prime then a(n) = the smallest number not yet in the sequence. Otherwise a(n) = a(n-1) + n - 1.

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	4
5	8
6	13
7	5
8	6
9	14
10	23
11	7
12	9
13	21
14	34
15	48
16	63
17	79
18	10
19	28
20	47
21	11
22	12
23	34
24	57
25	81
26	106
27	132
28	159
29	187
30	216
31	246
32	277
33	15
34	48
35	82
36	117
37	153
38	190
39	228
40	267
41	307
42	16
43	58
44	101
45	17
46	18
47	64
48	111
49	159
50	208
51	258
52	309
53	361
54	414
55	468
56	523
57	19
58	20
59	78
60	137
61	22
62	83
63	24
64	87
65	151
66	25
67	91

n	a(n)
1	1
2	2
3	3
4	4
5	8
6	13
7	5
8	6
9	14
10	23
11	7
12	9
13	21
14	34
15	48
16	63
17	79
18	10
19	28
20	47
21	11
22	12
23	34
24	57
25	81
26	106
27	132
28	159
29	187
30	216
31	246
32	277
33	15
34	48
35	82
36	117
37	153
38	190
39	228
40	267
41	307
42	16
43	58
44	101
45	17
46	18
47	64
48	111
49	159
50	208
51	258
52	309
53	361
54	414
55	468
56	523
57	19
58	20
59	78
60	137
61	22
62	83
63	24
64	87
65	151
66	25
67	91

n	a(n)
1	1
2	2
3	3
4	4
5	8
6	13
7	5
8	6
9	14
10	23
11	7
12	9
13	21
14	34
15	48
16	63
17	79
18	10
19	28
20	47
21	11
22	12
23	34
24	57
25	81
26	106
27	132
28	159
29	187
30	216
31	246
32	277
33	15
34	48
35	82
36	117
37	153
38	190
39	228
40	267
41	307
42	16
43	58
44	101
45	17
46	18
47	64
48	111
49	159
50	208
51	258
52	309
53	361
54	414
55	468
56	523
57	19
58	20
59	78
60	137
61	22
62	83
63	24
64	87
65	151
66	25
67	91