A209686 - cp's OEIS frontend

A209686 For each n, define a sequence of numbers by S(0)=n, S(i) = sum of last three digits of the concatenation S(0)S(1)S(2)...S(i-1); a(n) = smallest m such that S(m) = 11, or -1 if 11 is never reached.

n	a(n)
0	-1
1	6
2	8
3	14
4	7
5	6
6	13
7	16
8	6
9	7
10	5
11	0
12	3
13	8
14	6
15	13
16	16
17	6
18	7
19	7
20	15
21	11
22	7
23	6
24	13
25	16
26	6
27	7
28	9
29	1
30	9
31	15
32	6
33	13
34	16
35	6
36	7
37	12
38	1
39	10
40	4
41	6
42	13
43	16
44	6
45	7
46	9
47	1
48	2
49	4
50	6
51	13
52	16
53	6
54	7
55	5
56	1
57	20
58	13
59	-1
60	13
61	16
62	6
63	7
64	4
65	1
66	12
67	2
68	5
69	3
70	16
71	6
72	7
73	10
74	1
75	3
76	11
77	15
78	6
79	13
80	6
81	7
82	19
83	1
84	14
85	6
86	2
87	7
88	5
89	9
90	7
91	9
92	1
93	12
94	4
95	5

[-1, 6, 8, 14, 7, 6, 13, 16, 6, 7, 5, 0, 3, 8, 6, 13, 16, 6, 7, 7, 15, 11, 7, 6, 13, 16, 6, 7, 9, 1, 9, 15, 6, 13, 16, 6, 7, 12, 1, 10, 4, 6, 13, 16, 6, 7, 9, 1, 2, 4, 6, 13, 16, 6, 7, 5, 1, 20, 13, -1, 13, 16, 6, 7, 4, 1, 12, 2, 5, 3, 16, 6, 7, 10, 1, 3, 11, 15, 6, 13, 6, 7, 19, 1, 14, 6, 2, 7, 5, 9, 7, 9, 1, 12, 4, 5]

cp's OEIS Frontend

A209686 For each n, define a sequence of numbers by S(0)=n, S(i) = sum of last three digits of the concatenation S(0)S(1)S(2)...S(i-1); a(n) = smallest m such that S(m) = 11, or -1 if 11 is never reached.

Table of values

List of values

n	a(n)
0	-1
1	6
2	8
3	14
4	7
5	6
6	13
7	16
8	6
9	7
10	5
11	0
12	3
13	8
14	6
15	13
16	16
17	6
18	7
19	7
20	15
21	11
22	7
23	6
24	13
25	16
26	6
27	7
28	9
29	1
30	9
31	15
32	6
33	13
34	16
35	6
36	7
37	12
38	1
39	10
40	4
41	6
42	13
43	16
44	6
45	7
46	9
47	1
48	2
49	4
50	6
51	13
52	16
53	6
54	7
55	5
56	1
57	20
58	13
59	-1
60	13
61	16
62	6
63	7
64	4
65	1
66	12
67	2
68	5
69	3
70	16
71	6
72	7
73	10
74	1
75	3
76	11
77	15
78	6
79	13
80	6
81	7
82	19
83	1
84	14
85	6
86	2
87	7
88	5
89	9
90	7
91	9
92	1
93	12
94	4
95	5

n	a(n)
0	-1
1	6
2	8
3	14
4	7
5	6
6	13
7	16
8	6
9	7
10	5
11	0
12	3
13	8
14	6
15	13
16	16
17	6
18	7
19	7
20	15
21	11
22	7
23	6
24	13
25	16
26	6
27	7
28	9
29	1
30	9
31	15
32	6
33	13
34	16
35	6
36	7
37	12
38	1
39	10
40	4
41	6
42	13
43	16
44	6
45	7
46	9
47	1
48	2
49	4
50	6
51	13
52	16
53	6
54	7
55	5
56	1
57	20
58	13
59	-1
60	13
61	16
62	6
63	7
64	4
65	1
66	12
67	2
68	5
69	3
70	16
71	6
72	7
73	10
74	1
75	3
76	11
77	15
78	6
79	13
80	6
81	7
82	19
83	1
84	14
85	6
86	2
87	7
88	5
89	9
90	7
91	9
92	1
93	12
94	4
95	5

n	a(n)
0	-1
1	6
2	8
3	14
4	7
5	6
6	13
7	16
8	6
9	7
10	5
11	0
12	3
13	8
14	6
15	13
16	16
17	6
18	7
19	7
20	15
21	11
22	7
23	6
24	13
25	16
26	6
27	7
28	9
29	1
30	9
31	15
32	6
33	13
34	16
35	6
36	7
37	12
38	1
39	10
40	4
41	6
42	13
43	16
44	6
45	7
46	9
47	1
48	2
49	4
50	6
51	13
52	16
53	6
54	7
55	5
56	1
57	20
58	13
59	-1
60	13
61	16
62	6
63	7
64	4
65	1
66	12
67	2
68	5
69	3
70	16
71	6
72	7
73	10
74	1
75	3
76	11
77	15
78	6
79	13
80	6
81	7
82	19
83	1
84	14
85	6
86	2
87	7
88	5
89	9
90	7
91	9
92	1
93	12
94	4
95	5