A076423 - cp's OEIS frontend

A076423 Number of iterations of the mapping k -> abs(reverse(lpd(k))-reverse(gpf(k))) to reach zero, or -1 if zero is never reached. lpd(k) is the largest proper divisor and gpf(k) is the greatest prime factor of k.

n	a(n)
1	1
2	2
3	3
4	1
5	2
6	1
7	2
8	3
9	1
10	1
11	2
12	4
13	3
14	1
15	1
16	2
17	3
18	2
19	3
20	2
21	1
22	1
23	6
24	3
25	1
26	1
27	2
28	2
29	2
30	2
31	5
32	3
33	1
34	1
35	1
36	3
37	5
38	1
39	1
40	4
41	4
42	3
43	2
44	3
45	2
46	1
47	5
48	2
49	1
50	6
51	1
52	6
53	2
54	2
55	1
56	7
57	1
58	1
59	2
60	3
61	2
62	1
63	3
64	2
65	1
66	2
67	7
68	3
69	1
70	2
71	3
72	4
73	4
74	1
75	6
76	4
77	1
78	2
79	4
80	2
81	2
82	1
83	6
84	4
85	1
86	1
87	1
88	2
89	4
90	2
91	1
92	4
93	1
94	1
95	1
96	3
97	3
98	2
99	2
100	1
101	2
102	8
103	3
104	2
105	2

[1, 2, 3, 1, 2, 1, 2, 3, 1, 1, 2, 4, 3, 1, 1, 2, 3, 2, 3, 2, 1, 1, 6, 3, 1, 1, 2, 2, 2, 2, 5, 3, 1, 1, 1, 3, 5, 1, 1, 4, 4, 3, 2, 3, 2, 1, 5, 2, 1, 6, 1, 6, 2, 2, 1, 7, 1, 1, 2, 3, 2, 1, 3, 2, 1, 2, 7, 3, 1, 2, 3, 4, 4, 1, 6, 4, 1, 2, 4, 2, 2, 1, 6, 4, 1, 1, 1, 2, 4, 2, 1, 4, 1, 1, 1, 3, 3, 2, 2, 1, 2, 8, 3, 2, 2]

cp's OEIS Frontend

A076423 Number of iterations of the mapping k -> abs(reverse(lpd(k))-reverse(gpf(k))) to reach zero, or -1 if zero is never reached. lpd(k) is the largest proper divisor and gpf(k) is the greatest prime factor of k.

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	1
5	2
6	1
7	2
8	3
9	1
10	1
11	2
12	4
13	3
14	1
15	1
16	2
17	3
18	2
19	3
20	2
21	1
22	1
23	6
24	3
25	1
26	1
27	2
28	2
29	2
30	2
31	5
32	3
33	1
34	1
35	1
36	3
37	5
38	1
39	1
40	4
41	4
42	3
43	2
44	3
45	2
46	1
47	5
48	2
49	1
50	6
51	1
52	6
53	2
54	2
55	1
56	7
57	1
58	1
59	2
60	3
61	2
62	1
63	3
64	2
65	1
66	2
67	7
68	3
69	1
70	2
71	3
72	4
73	4
74	1
75	6
76	4
77	1
78	2
79	4
80	2
81	2
82	1
83	6
84	4
85	1
86	1
87	1
88	2
89	4
90	2
91	1
92	4
93	1
94	1
95	1
96	3
97	3
98	2
99	2
100	1
101	2
102	8
103	3
104	2
105	2

n	a(n)
1	1
2	2
3	3
4	1
5	2
6	1
7	2
8	3
9	1
10	1
11	2
12	4
13	3
14	1
15	1
16	2
17	3
18	2
19	3
20	2
21	1
22	1
23	6
24	3
25	1
26	1
27	2
28	2
29	2
30	2
31	5
32	3
33	1
34	1
35	1
36	3
37	5
38	1
39	1
40	4
41	4
42	3
43	2
44	3
45	2
46	1
47	5
48	2
49	1
50	6
51	1
52	6
53	2
54	2
55	1
56	7
57	1
58	1
59	2
60	3
61	2
62	1
63	3
64	2
65	1
66	2
67	7
68	3
69	1
70	2
71	3
72	4
73	4
74	1
75	6
76	4
77	1
78	2
79	4
80	2
81	2
82	1
83	6
84	4
85	1
86	1
87	1
88	2
89	4
90	2
91	1
92	4
93	1
94	1
95	1
96	3
97	3
98	2
99	2
100	1
101	2
102	8
103	3
104	2
105	2

n	a(n)
1	1
2	2
3	3
4	1
5	2
6	1
7	2
8	3
9	1
10	1
11	2
12	4
13	3
14	1
15	1
16	2
17	3
18	2
19	3
20	2
21	1
22	1
23	6
24	3
25	1
26	1
27	2
28	2
29	2
30	2
31	5
32	3
33	1
34	1
35	1
36	3
37	5
38	1
39	1
40	4
41	4
42	3
43	2
44	3
45	2
46	1
47	5
48	2
49	1
50	6
51	1
52	6
53	2
54	2
55	1
56	7
57	1
58	1
59	2
60	3
61	2
62	1
63	3
64	2
65	1
66	2
67	7
68	3
69	1
70	2
71	3
72	4
73	4
74	1
75	6
76	4
77	1
78	2
79	4
80	2
81	2
82	1
83	6
84	4
85	1
86	1
87	1
88	2
89	4
90	2
91	1
92	4
93	1
94	1
95	1
96	3
97	3
98	2
99	2
100	1
101	2
102	8
103	3
104	2
105	2