A339793 - cp's OEIS frontend

A339793 a(1) = 1, a(2) = 2; for n > 2, a(n) is the smallest positive number not occurring earlier that is a multiple of s(a(n-1)), the sum of the proper divisors of a(n-1).

n	a(n)
1	1
2	2
3	3
4	4
5	6
6	12
7	16
8	15
9	9
10	8
11	7
12	5
13	10
14	24
15	36
16	55
17	17
18	11
19	13
20	14
21	20
22	22
23	28
24	56
25	64
26	63
27	41
28	18
29	21
30	33
31	30
32	42
33	54
34	66
35	78
36	90
37	144
38	259
39	45
40	99
41	57
42	23
43	19
44	25
45	48
46	76
47	128
48	127
49	26
50	32
51	31
52	27
53	39
54	34
55	40
56	50
57	43
58	29
59	35
60	52
61	46
62	104
63	106
64	112
65	136
66	134
67	70
68	74
69	80
70	212
71	166
72	86
73	92
74	152

[1, 2, 3, 4, 6, 12, 16, 15, 9, 8, 7, 5, 10, 24, 36, 55, 17, 11, 13, 14, 20, 22, 28, 56, 64, 63, 41, 18, 21, 33, 30, 42, 54, 66, 78, 90, 144, 259, 45, 99, 57, 23, 19, 25, 48, 76, 128, 127, 26, 32, 31, 27, 39, 34, 40, 50, 43, 29, 35, 52, 46, 104, 106, 112, 136, 134, 70, 74, 80, 212, 166, 86, 92, 152]

cp's OEIS Frontend

A339793 a(1) = 1, a(2) = 2; for n > 2, a(n) is the smallest positive number not occurring earlier that is a multiple of s(a(n-1)), the sum of the proper divisors of a(n-1).

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	4
5	6
6	12
7	16
8	15
9	9
10	8
11	7
12	5
13	10
14	24
15	36
16	55
17	17
18	11
19	13
20	14
21	20
22	22
23	28
24	56
25	64
26	63
27	41
28	18
29	21
30	33
31	30
32	42
33	54
34	66
35	78
36	90
37	144
38	259
39	45
40	99
41	57
42	23
43	19
44	25
45	48
46	76
47	128
48	127
49	26
50	32
51	31
52	27
53	39
54	34
55	40
56	50
57	43
58	29
59	35
60	52
61	46
62	104
63	106
64	112
65	136
66	134
67	70
68	74
69	80
70	212
71	166
72	86
73	92
74	152

n	a(n)
1	1
2	2
3	3
4	4
5	6
6	12
7	16
8	15
9	9
10	8
11	7
12	5
13	10
14	24
15	36
16	55
17	17
18	11
19	13
20	14
21	20
22	22
23	28
24	56
25	64
26	63
27	41
28	18
29	21
30	33
31	30
32	42
33	54
34	66
35	78
36	90
37	144
38	259
39	45
40	99
41	57
42	23
43	19
44	25
45	48
46	76
47	128
48	127
49	26
50	32
51	31
52	27
53	39
54	34
55	40
56	50
57	43
58	29
59	35
60	52
61	46
62	104
63	106
64	112
65	136
66	134
67	70
68	74
69	80
70	212
71	166
72	86
73	92
74	152

n	a(n)
1	1
2	2
3	3
4	4
5	6
6	12
7	16
8	15
9	9
10	8
11	7
12	5
13	10
14	24
15	36
16	55
17	17
18	11
19	13
20	14
21	20
22	22
23	28
24	56
25	64
26	63
27	41
28	18
29	21
30	33
31	30
32	42
33	54
34	66
35	78
36	90
37	144
38	259
39	45
40	99
41	57
42	23
43	19
44	25
45	48
46	76
47	128
48	127
49	26
50	32
51	31
52	27
53	39
54	34
55	40
56	50
57	43
58	29
59	35
60	52
61	46
62	104
63	106
64	112
65	136
66	134
67	70
68	74
69	80
70	212
71	166
72	86
73	92
74	152