A230107 - cp's OEIS frontend

A230107 Define a sequence by b(1)=n, b(k+1)=b(k)+(sum of digits of b(k)); a(n) is the number of steps needed to reach a term in A004207, or a(n) = -1 if the sequence never joins A004207.

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

[0, 0, -1, 0, 52, -1, 11, 0, -1, 51, 50, -1, 49, 10, -1, 0, 48, -1, 9, 50, -1, 49, 0, -1, 47, 48, -1, 0, 8, -1, 49, 46, -1, 47, 48, -1, 45, 0, -1, 7, 46, -1, 47, 6, -1, 45, 44, -1, 0, 46, -1, 5, 5, -1, 45, 44, -1, 43, 4, -1, 4, 0, -1, 4, 44, -1, 43, 3, -1, 0]

cp's OEIS Frontend

A230107 Define a sequence by b(1)=n, b(k+1)=b(k)+(sum of digits of b(k)); a(n) is the number of steps needed to reach a term in A004207, or a(n) = -1 if the sequence never joins A004207.

Table of values

List of values

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

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

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