A023820 - cp's OEIS frontend

A023820 Sum of exponents in prime-power factorization of C(3n,n-1).

n	a(n)
1	0
2	2
3	4
4	4
5	4
6	7
7	7
8	8
9	8
10	8
11	11
12	12
13	9
14	12
15	13
16	12
17	11
18	13
19	14
20	15
21	14
22	17
23	18
24	19
25	16
26	18
27	20
28	18
29	18
30	21
31	20
32	21
33	19
34	20
35	22
36	22
37	19
38	22
39	24
40	22
41	21
42	24
43	27
44	29
45	28
46	28
47	29
48	31
49	27
50	28
51	29
52	29
53	28
54	34
55	32
56	32
57	31
58	30
59	34
60	34
61	32
62	34
63	36
64	35
65	31
66	32
67	31
68	33
69	33
70	36
71	35
72	36
73	32
74	36
75	40
76	37
77	36
78	38

[0, 2, 4, 4, 4, 7, 7, 8, 8, 8, 11, 12, 9, 12, 13, 12, 11, 13, 14, 15, 14, 17, 18, 19, 16, 18, 20, 18, 18, 21, 20, 21, 19, 20, 22, 22, 19, 22, 24, 22, 21, 24, 27, 29, 28, 28, 29, 31, 27, 28, 29, 29, 28, 34, 32, 32, 31, 30, 34, 34, 32, 34, 36, 35, 31, 32, 31, 33, 33, 36, 35, 36, 32, 36, 40, 37, 36, 38]

cp's OEIS Frontend

A023820 Sum of exponents in prime-power factorization of C(3n,n-1).

Table of values

List of values

n	a(n)
1	0
2	2
3	4
4	4
5	4
6	7
7	7
8	8
9	8
10	8
11	11
12	12
13	9
14	12
15	13
16	12
17	11
18	13
19	14
20	15
21	14
22	17
23	18
24	19
25	16
26	18
27	20
28	18
29	18
30	21
31	20
32	21
33	19
34	20
35	22
36	22
37	19
38	22
39	24
40	22
41	21
42	24
43	27
44	29
45	28
46	28
47	29
48	31
49	27
50	28
51	29
52	29
53	28
54	34
55	32
56	32
57	31
58	30
59	34
60	34
61	32
62	34
63	36
64	35
65	31
66	32
67	31
68	33
69	33
70	36
71	35
72	36
73	32
74	36
75	40
76	37
77	36
78	38

n	a(n)
1	0
2	2
3	4
4	4
5	4
6	7
7	7
8	8
9	8
10	8
11	11
12	12
13	9
14	12
15	13
16	12
17	11
18	13
19	14
20	15
21	14
22	17
23	18
24	19
25	16
26	18
27	20
28	18
29	18
30	21
31	20
32	21
33	19
34	20
35	22
36	22
37	19
38	22
39	24
40	22
41	21
42	24
43	27
44	29
45	28
46	28
47	29
48	31
49	27
50	28
51	29
52	29
53	28
54	34
55	32
56	32
57	31
58	30
59	34
60	34
61	32
62	34
63	36
64	35
65	31
66	32
67	31
68	33
69	33
70	36
71	35
72	36
73	32
74	36
75	40
76	37
77	36
78	38

n	a(n)
1	0
2	2
3	4
4	4
5	4
6	7
7	7
8	8
9	8
10	8
11	11
12	12
13	9
14	12
15	13
16	12
17	11
18	13
19	14
20	15
21	14
22	17
23	18
24	19
25	16
26	18
27	20
28	18
29	18
30	21
31	20
32	21
33	19
34	20
35	22
36	22
37	19
38	22
39	24
40	22
41	21
42	24
43	27
44	29
45	28
46	28
47	29
48	31
49	27
50	28
51	29
52	29
53	28
54	34
55	32
56	32
57	31
58	30
59	34
60	34
61	32
62	34
63	36
64	35
65	31
66	32
67	31
68	33
69	33
70	36
71	35
72	36
73	32
74	36
75	40
76	37
77	36
78	38