A341035 - cp's OEIS frontend

A341035 a(n) is the smallest positive integer such that n+a(n) contains the string n-a(n), in both forward and reverse directions, as a substring. If no such number exists then a(n) = -1.

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

[-1, -1, -1, -1, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 10, 10, 10, 10, 10, 15, 15, 15, 15, 15, 20, 20, 20, 20, 20, 25, 25, 25, 25, 25, 29, 30, 30, 30, 30, 33, 34, 35, 35, 35, 37, 38, 39, 40, 40, 41, 42, 43, 44, 45, 50, 50, 50, 50, 50, 55, 50, 51, 52, 53, 54, 60, 60, 60, 60, 65, 50, 50, 65, 65, 70, 70, 70]

cp's OEIS Frontend

A341035 a(n) is the smallest positive integer such that n+a(n) contains the string n-a(n), in both forward and reverse directions, as a substring. If no such number exists then a(n) = -1.

Table of values

List of values

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

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

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