A337980 - cp's OEIS frontend

A337980 When terms first appear in the sequence they are "untouched". Start with a(1)=1. Thereafter, to find a(n), let k = a(n-1). If there is an earlier occurrence a(n-m) = k which is untouched, then a(n) = m and a(n-m) is now "touched". Otherwise, a(n) = 0.

n	a(n)
1	1
2	0
3	0
4	2
5	0
6	3
7	0
8	3
9	3
10	2
11	7
12	0
13	6
14	0
15	3
16	7
17	6
18	5
19	0
20	6
21	4
22	0
23	4
24	3
25	10
26	0
27	5
28	10
29	4
30	7
31	15
32	0
33	7
34	4
35	6
36	16
37	0
38	6
39	4
40	6
41	3
42	18
43	0
44	7
45	12
46	0
47	4
48	9
49	0
50	4
51	4
52	2
53	43
54	0
55	6
56	16
57	21
58	0
59	5
60	33
61	0
62	4
63	12
64	19
65	0
66	5
67	8
68	0
69	4
70	8
71	4
72	3
73	32
74	0
75	7
76	32
77	4
78	7
79	4
80	3
81	9
82	34
83	0
84	10
85	57

[1, 0, 0, 2, 0, 3, 0, 3, 3, 2, 7, 0, 6, 0, 3, 7, 6, 5, 0, 6, 4, 0, 4, 3, 10, 0, 5, 10, 4, 7, 15, 0, 7, 4, 6, 16, 0, 6, 4, 6, 3, 18, 0, 7, 12, 0, 4, 9, 0, 4, 4, 2, 43, 0, 6, 16, 21, 0, 5, 33, 0, 4, 12, 19, 0, 5, 8, 0, 4, 8, 4, 3, 32, 0, 7, 32, 4, 7, 4, 3, 9, 34, 0, 10, 57]

cp's OEIS Frontend

A337980 When terms first appear in the sequence they are "untouched". Start with a(1)=1. Thereafter, to find a(n), let k = a(n-1). If there is an earlier occurrence a(n-m) = k which is untouched, then a(n) = m and a(n-m) is now "touched". Otherwise, a(n) = 0.

Table of values

List of values

n	a(n)
1	1
2	0
3	0
4	2
5	0
6	3
7	0
8	3
9	3
10	2
11	7
12	0
13	6
14	0
15	3
16	7
17	6
18	5
19	0
20	6
21	4
22	0
23	4
24	3
25	10
26	0
27	5
28	10
29	4
30	7
31	15
32	0
33	7
34	4
35	6
36	16
37	0
38	6
39	4
40	6
41	3
42	18
43	0
44	7
45	12
46	0
47	4
48	9
49	0
50	4
51	4
52	2
53	43
54	0
55	6
56	16
57	21
58	0
59	5
60	33
61	0
62	4
63	12
64	19
65	0
66	5
67	8
68	0
69	4
70	8
71	4
72	3
73	32
74	0
75	7
76	32
77	4
78	7
79	4
80	3
81	9
82	34
83	0
84	10
85	57

n	a(n)
1	1
2	0
3	0
4	2
5	0
6	3
7	0
8	3
9	3
10	2
11	7
12	0
13	6
14	0
15	3
16	7
17	6
18	5
19	0
20	6
21	4
22	0
23	4
24	3
25	10
26	0
27	5
28	10
29	4
30	7
31	15
32	0
33	7
34	4
35	6
36	16
37	0
38	6
39	4
40	6
41	3
42	18
43	0
44	7
45	12
46	0
47	4
48	9
49	0
50	4
51	4
52	2
53	43
54	0
55	6
56	16
57	21
58	0
59	5
60	33
61	0
62	4
63	12
64	19
65	0
66	5
67	8
68	0
69	4
70	8
71	4
72	3
73	32
74	0
75	7
76	32
77	4
78	7
79	4
80	3
81	9
82	34
83	0
84	10
85	57

n	a(n)
1	1
2	0
3	0
4	2
5	0
6	3
7	0
8	3
9	3
10	2
11	7
12	0
13	6
14	0
15	3
16	7
17	6
18	5
19	0
20	6
21	4
22	0
23	4
24	3
25	10
26	0
27	5
28	10
29	4
30	7
31	15
32	0
33	7
34	4
35	6
36	16
37	0
38	6
39	4
40	6
41	3
42	18
43	0
44	7
45	12
46	0
47	4
48	9
49	0
50	4
51	4
52	2
53	43
54	0
55	6
56	16
57	21
58	0
59	5
60	33
61	0
62	4
63	12
64	19
65	0
66	5
67	8
68	0
69	4
70	8
71	4
72	3
73	32
74	0
75	7
76	32
77	4
78	7
79	4
80	3
81	9
82	34
83	0
84	10
85	57