A031346 - cp's OEIS frontend

A031346 Multiplicative persistence: number of iterations of "multiply digits" needed to reach a number < 10.

n	a(n)
0	0
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	0
10	1
11	1
12	1
13	1
14	1
15	1
16	1
17	1
18	1
19	1
20	1
21	1
22	1
23	1
24	1
25	2
26	2
27	2
28	2
29	2
30	1
31	1
32	1
33	1
34	2
35	2
36	2
37	2
38	2
39	3
40	1
41	1
42	1
43	2
44	2
45	2
46	2
47	3
48	2
49	3
50	1
51	1
52	2
53	2
54	2
55	3
56	2
57	3
58	2
59	3
60	1
61	1
62	2
63	2
64	2
65	2
66	3
67	2
68	3
69	3
70	1
71	1
72	2
73	2
74	3
75	3
76	2
77	4
78	3
79	3
80	1
81	1
82	2
83	2
84	2
85	2
86	3
87	3
88	3
89	3
90	1
91	1
92	2
93	3
94	3
95	3
96	3
97	3
98	3
99	2

[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 1, 1, 1, 2, 2, 2, 2, 3, 2, 3, 1, 1, 2, 2, 2, 3, 2, 3, 2, 3, 1, 1, 2, 2, 2, 2, 3, 2, 3, 3, 1, 1, 2, 2, 3, 3, 2, 4, 3, 3, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 1, 1, 2, 3, 3, 3, 3, 3, 3, 2]

cp's OEIS Frontend

A031346 Multiplicative persistence: number of iterations of "multiply digits" needed to reach a number < 10.

Table of values

List of values

n	a(n)
0	0
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	0
10	1
11	1
12	1
13	1
14	1
15	1
16	1
17	1
18	1
19	1
20	1
21	1
22	1
23	1
24	1
25	2
26	2
27	2
28	2
29	2
30	1
31	1
32	1
33	1
34	2
35	2
36	2
37	2
38	2
39	3
40	1
41	1
42	1
43	2
44	2
45	2
46	2
47	3
48	2
49	3
50	1
51	1
52	2
53	2
54	2
55	3
56	2
57	3
58	2
59	3
60	1
61	1
62	2
63	2
64	2
65	2
66	3
67	2
68	3
69	3
70	1
71	1
72	2
73	2
74	3
75	3
76	2
77	4
78	3
79	3
80	1
81	1
82	2
83	2
84	2
85	2
86	3
87	3
88	3
89	3
90	1
91	1
92	2
93	3
94	3
95	3
96	3
97	3
98	3
99	2

n	a(n)
0	0
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	0
10	1
11	1
12	1
13	1
14	1
15	1
16	1
17	1
18	1
19	1
20	1
21	1
22	1
23	1
24	1
25	2
26	2
27	2
28	2
29	2
30	1
31	1
32	1
33	1
34	2
35	2
36	2
37	2
38	2
39	3
40	1
41	1
42	1
43	2
44	2
45	2
46	2
47	3
48	2
49	3
50	1
51	1
52	2
53	2
54	2
55	3
56	2
57	3
58	2
59	3
60	1
61	1
62	2
63	2
64	2
65	2
66	3
67	2
68	3
69	3
70	1
71	1
72	2
73	2
74	3
75	3
76	2
77	4
78	3
79	3
80	1
81	1
82	2
83	2
84	2
85	2
86	3
87	3
88	3
89	3
90	1
91	1
92	2
93	3
94	3
95	3
96	3
97	3
98	3
99	2

n	a(n)
0	0
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	0
10	1
11	1
12	1
13	1
14	1
15	1
16	1
17	1
18	1
19	1
20	1
21	1
22	1
23	1
24	1
25	2
26	2
27	2
28	2
29	2
30	1
31	1
32	1
33	1
34	2
35	2
36	2
37	2
38	2
39	3
40	1
41	1
42	1
43	2
44	2
45	2
46	2
47	3
48	2
49	3
50	1
51	1
52	2
53	2
54	2
55	3
56	2
57	3
58	2
59	3
60	1
61	1
62	2
63	2
64	2
65	2
66	3
67	2
68	3
69	3
70	1
71	1
72	2
73	2
74	3
75	3
76	2
77	4
78	3
79	3
80	1
81	1
82	2
83	2
84	2
85	2
86	3
87	3
88	3
89	3
90	1
91	1
92	2
93	3
94	3
95	3
96	3
97	3
98	3
99	2