A256393 - cp's OEIS frontend

A256393 Start from a(1) = 2, then alternately add either the largest (if n is even), or the smallest (if n is odd) prime factor of the preceding term a(n-1) to get a(n).

n	a(n)
1	2
2	4
3	6
4	9
5	12
6	15
7	18
8	21
9	24
10	27
11	30
12	35
13	40
14	45
15	48
16	51
17	54
18	57
19	60
20	65
21	70
22	77
23	84
24	91
25	98
26	105
27	108
28	111
29	114
30	133
31	140
32	147
33	150
34	155
35	160
36	165
37	168
38	175
39	180
40	185
41	190
42	209
43	220
44	231
45	234
46	247
47	260
48	273
49	276
50	299
51	312
52	325
53	330
54	341
55	352
56	363
57	366
58	427

[2, 4, 6, 9, 12, 15, 18, 21, 24, 27, 30, 35, 40, 45, 48, 51, 54, 57, 60, 65, 70, 77, 84, 91, 98, 105, 108, 111, 114, 133, 140, 147, 150, 155, 160, 165, 168, 175, 180, 185, 190, 209, 220, 231, 234, 247, 260, 273, 276, 299, 312, 325, 330, 341, 352, 363, 366, 427]

cp's OEIS Frontend

A256393 Start from a(1) = 2, then alternately add either the largest (if n is even), or the smallest (if n is odd) prime factor of the preceding term a(n-1) to get a(n).

Table of values

List of values

n	a(n)
1	2
2	4
3	6
4	9
5	12
6	15
7	18
8	21
9	24
10	27
11	30
12	35
13	40
14	45
15	48
16	51
17	54
18	57
19	60
20	65
21	70
22	77
23	84
24	91
25	98
26	105
27	108
28	111
29	114
30	133
31	140
32	147
33	150
34	155
35	160
36	165
37	168
38	175
39	180
40	185
41	190
42	209
43	220
44	231
45	234
46	247
47	260
48	273
49	276
50	299
51	312
52	325
53	330
54	341
55	352
56	363
57	366
58	427

n	a(n)
1	2
2	4
3	6
4	9
5	12
6	15
7	18
8	21
9	24
10	27
11	30
12	35
13	40
14	45
15	48
16	51
17	54
18	57
19	60
20	65
21	70
22	77
23	84
24	91
25	98
26	105
27	108
28	111
29	114
30	133
31	140
32	147
33	150
34	155
35	160
36	165
37	168
38	175
39	180
40	185
41	190
42	209
43	220
44	231
45	234
46	247
47	260
48	273
49	276
50	299
51	312
52	325
53	330
54	341
55	352
56	363
57	366
58	427

n	a(n)
1	2
2	4
3	6
4	9
5	12
6	15
7	18
8	21
9	24
10	27
11	30
12	35
13	40
14	45
15	48
16	51
17	54
18	57
19	60
20	65
21	70
22	77
23	84
24	91
25	98
26	105
27	108
28	111
29	114
30	133
31	140
32	147
33	150
34	155
35	160
36	165
37	168
38	175
39	180
40	185
41	190
42	209
43	220
44	231
45	234
46	247
47	260
48	273
49	276
50	299
51	312
52	325
53	330
54	341
55	352
56	363
57	366
58	427