A102641 - cp's OEIS frontend

A102641 Compute the greatest prime factors (GPFs, A006530()) of -j + 2^n for j = 0, 1, ..., L. a(n) is the maximal length L of such a sequence in which the greatest prime factors are increasing with decreasing j.

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

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

cp's OEIS Frontend

A102641 Compute the greatest prime factors (GPFs, A006530()) of -j + 2^n for j = 0, 1, ..., L. a(n) is the maximal length L of such a sequence in which the greatest prime factors are increasing with decreasing j.

Table of values

List of values

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

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

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