A372490 - cp's OEIS frontend

A372490 Minimum integer such that the convergence speed of the tetration n^^(a(n)) is constant (i.e., the convergence speed of n^^(a(n) + m) is a fixed number for any positive integer m) and -1 if n is a multiple of 10.

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

[3, 2, 2, 4, 3, 2, 2, 1, -1, 2, 2, 1, 2, 3, 2, 1, 3, 1, -1, 2, 3, 2, 2, 3, 3, 2, 2, 1, -1, 2, 2, 1, 2, 3, 2, 1, 3, 1, -1, 2, 3, 2, 2, 3, 3, 2, 2, 1, -1, 2, 2, 1, 2, 3, 2, 1, 3, 1, -1, 2, 3, 2, 2, 3, 3, 2, 2, 1, -1, 2, 2, 1, 2, 3, 3, 1, 3, 1, -1, 2, 3, 2, 2, 3]

cp's OEIS Frontend

A372490 Minimum integer such that the convergence speed of the tetration n^^(a(n)) is constant (i.e., the convergence speed of n^^(a(n) + m) is a fixed number for any positive integer m) and -1 if n is a multiple of 10.

Table of values

List of values

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

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

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