A347769 - cp's OEIS frontend

A347769 a(0) = 0; a(1) = 1; for n > 1, a(n) = A001065(a(n-1)) = sigma(a(n-1)) - a(n-1) (the sum of aliquot parts of a(n-1)) if this is not yet in the sequence; otherwise a(n) is the smallest number missing from the sequence.

n	a(n)
0	0
1	1
2	2
3	3
4	4
5	5
6	6
7	7
8	8
9	9
10	10
11	11
12	12
13	16
14	15
15	13
16	14
17	17
18	18
19	21
20	19
21	20
22	22
23	23
24	24
25	36
26	55
27	25
28	26
29	27
30	28
31	29
32	30
33	42
34	54
35	66
36	78
37	90
38	144
39	259
40	45
41	33
42	31
43	32
44	34
45	35
46	37
47	38
48	39
49	40
50	50
51	43
52	41
53	44
54	46
55	47
56	48
57	76
58	64
59	63
60	49
61	51
62	52
63	53
64	56
65	57
66	58
67	59
68	60
69	108
70	172

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 16, 15, 13, 14, 17, 18, 21, 19, 20, 22, 23, 24, 36, 55, 25, 26, 27, 28, 29, 30, 42, 54, 66, 78, 90, 144, 259, 45, 33, 31, 32, 34, 35, 37, 38, 39, 40, 50, 43, 41, 44, 46, 47, 48, 76, 64, 63, 49, 51, 52, 53, 56, 57, 58, 59, 60, 108, 172]

cp's OEIS Frontend

A347769 a(0) = 0; a(1) = 1; for n > 1, a(n) = A001065(a(n-1)) = sigma(a(n-1)) - a(n-1) (the sum of aliquot parts of a(n-1)) if this is not yet in the sequence; otherwise a(n) is the smallest number missing from the sequence.

Table of values

List of values

n	a(n)
0	0
1	1
2	2
3	3
4	4
5	5
6	6
7	7
8	8
9	9
10	10
11	11
12	12
13	16
14	15
15	13
16	14
17	17
18	18
19	21
20	19
21	20
22	22
23	23
24	24
25	36
26	55
27	25
28	26
29	27
30	28
31	29
32	30
33	42
34	54
35	66
36	78
37	90
38	144
39	259
40	45
41	33
42	31
43	32
44	34
45	35
46	37
47	38
48	39
49	40
50	50
51	43
52	41
53	44
54	46
55	47
56	48
57	76
58	64
59	63
60	49
61	51
62	52
63	53
64	56
65	57
66	58
67	59
68	60
69	108
70	172

n	a(n)
0	0
1	1
2	2
3	3
4	4
5	5
6	6
7	7
8	8
9	9
10	10
11	11
12	12
13	16
14	15
15	13
16	14
17	17
18	18
19	21
20	19
21	20
22	22
23	23
24	24
25	36
26	55
27	25
28	26
29	27
30	28
31	29
32	30
33	42
34	54
35	66
36	78
37	90
38	144
39	259
40	45
41	33
42	31
43	32
44	34
45	35
46	37
47	38
48	39
49	40
50	50
51	43
52	41
53	44
54	46
55	47
56	48
57	76
58	64
59	63
60	49
61	51
62	52
63	53
64	56
65	57
66	58
67	59
68	60
69	108
70	172

n	a(n)
0	0
1	1
2	2
3	3
4	4
5	5
6	6
7	7
8	8
9	9
10	10
11	11
12	12
13	16
14	15
15	13
16	14
17	17
18	18
19	21
20	19
21	20
22	22
23	23
24	24
25	36
26	55
27	25
28	26
29	27
30	28
31	29
32	30
33	42
34	54
35	66
36	78
37	90
38	144
39	259
40	45
41	33
42	31
43	32
44	34
45	35
46	37
47	38
48	39
49	40
50	50
51	43
52	41
53	44
54	46
55	47
56	48
57	76
58	64
59	63
60	49
61	51
62	52
63	53
64	56
65	57
66	58
67	59
68	60
69	108
70	172