A278028 - cp's OEIS frontend

A278028 Let {c(i)} = A007916 denote the sequence of numbers > 1 which are not perfect powers. Every positive integer n has a unique representation as a tower n = c(x_1)^c(x_2)^c(x_3)^...^c(x_k), where the exponents are nested from the right. The sequence is an irregular triangle read by rows, where the n-th row lists x_1, ..., x_k.

n	a(n)
1	1
2	2
3	1
4	1
5	3
6	4
7	5
8	1
9	2
10	2
11	1
12	6
13	7
14	8
15	9
16	10
17	11
18	1
19	1
20	1
21	12
22	13
23	14
24	15
25	16
26	17
27	18
28	19
29	3
30	1
31	20
32	2
33	2
34	21
35	22
36	23
37	24
38	1
39	3
40	25
41	26
42	27
43	4
44	1
45	28
46	29
47	30
48	31

[1, 2, 1, 1, 3, 4, 5, 1, 2, 2, 1, 6, 7, 8, 9, 10, 11, 1, 1, 1, 12, 13, 14, 15, 16, 17, 18, 19, 3, 1, 20, 2, 2, 21, 22, 23, 24, 1, 3, 25, 26, 27, 4, 1, 28, 29, 30, 31]

cp's OEIS Frontend

Table of values

List of values

n	a(n)
1	1
2	2
3	1
4	1
5	3
6	4
7	5
8	1
9	2
10	2
11	1
12	6
13	7
14	8
15	9
16	10
17	11
18	1
19	1
20	1
21	12
22	13
23	14
24	15
25	16
26	17
27	18
28	19
29	3
30	1
31	20
32	2
33	2
34	21
35	22
36	23
37	24
38	1
39	3
40	25
41	26
42	27
43	4
44	1
45	28
46	29
47	30
48	31

n	a(n)
1	1
2	2
3	1
4	1
5	3
6	4
7	5
8	1
9	2
10	2
11	1
12	6
13	7
14	8
15	9
16	10
17	11
18	1
19	1
20	1
21	12
22	13
23	14
24	15
25	16
26	17
27	18
28	19
29	3
30	1
31	20
32	2
33	2
34	21
35	22
36	23
37	24
38	1
39	3
40	25
41	26
42	27
43	4
44	1
45	28
46	29
47	30
48	31

n	a(n)
1	1
2	2
3	1
4	1
5	3
6	4
7	5
8	1
9	2
10	2
11	1
12	6
13	7
14	8
15	9
16	10
17	11
18	1
19	1
20	1
21	12
22	13
23	14
24	15
25	16
26	17
27	18
28	19
29	3
30	1
31	20
32	2
33	2
34	21
35	22
36	23
37	24
38	1
39	3
40	25
41	26
42	27
43	4
44	1
45	28
46	29
47	30
48	31