A330573 - cp's OEIS frontend

A330573 a(n) = Sum_{k = 1..ceiling(n/2)} [u_2(k)u_2(n+1-k)], where u_2(k) is number of unordered factorization k = ij (A038548).

n	a(n)
0	0
1	1
2	1
3	2
4	3
5	4
6	5
7	8
8	7
9	10
10	10
11	14
12	14
13	16
14	16
15	22
16	20
17	26
18	24
19	30
20	28
21	34
22	30
23	43
24	36
25	43
26	40
27	51
28	44
29	56
30	49
31	63
32	55
33	66
34	55
35	78
36	64
37	75
38	70
39	89
40	72
41	93
42	77
43	98
44	87
45	103
46	84
47	122
48	94
49	115
50	104
51	127
52	102
53	136
54	109
55	141
56	123
57	143
58	117
59	170
60	128
61	153
62	138
63	174
64	138
65	183
66	143
67	183
68	161
69	189
70	152
71	224
72	163
73	200
74	180

[0, 1, 1, 2, 3, 4, 5, 8, 7, 10, 10, 14, 14, 16, 16, 22, 20, 26, 24, 30, 28, 34, 30, 43, 36, 43, 40, 51, 44, 56, 49, 63, 55, 66, 55, 78, 64, 75, 70, 89, 72, 93, 77, 98, 87, 103, 84, 122, 94, 115, 104, 127, 102, 136, 109, 141, 123, 143, 117, 170, 128, 153, 138, 174, 138, 183, 143, 183, 161, 189, 152, 224, 163, 200, 180]

cp's OEIS Frontend

A330573 a(n) = Sum_{k = 1..ceiling(n/2)} [u_2(k)u_2(n+1-k)], where u_2(k) is number of unordered factorization k = ij (A038548).

Table of values

List of values

n	a(n)
0	0
1	1
2	1
3	2
4	3
5	4
6	5
7	8
8	7
9	10
10	10
11	14
12	14
13	16
14	16
15	22
16	20
17	26
18	24
19	30
20	28
21	34
22	30
23	43
24	36
25	43
26	40
27	51
28	44
29	56
30	49
31	63
32	55
33	66
34	55
35	78
36	64
37	75
38	70
39	89
40	72
41	93
42	77
43	98
44	87
45	103
46	84
47	122
48	94
49	115
50	104
51	127
52	102
53	136
54	109
55	141
56	123
57	143
58	117
59	170
60	128
61	153
62	138
63	174
64	138
65	183
66	143
67	183
68	161
69	189
70	152
71	224
72	163
73	200
74	180

n	a(n)
0	0
1	1
2	1
3	2
4	3
5	4
6	5
7	8
8	7
9	10
10	10
11	14
12	14
13	16
14	16
15	22
16	20
17	26
18	24
19	30
20	28
21	34
22	30
23	43
24	36
25	43
26	40
27	51
28	44
29	56
30	49
31	63
32	55
33	66
34	55
35	78
36	64
37	75
38	70
39	89
40	72
41	93
42	77
43	98
44	87
45	103
46	84
47	122
48	94
49	115
50	104
51	127
52	102
53	136
54	109
55	141
56	123
57	143
58	117
59	170
60	128
61	153
62	138
63	174
64	138
65	183
66	143
67	183
68	161
69	189
70	152
71	224
72	163
73	200
74	180

cp's OEIS Frontend

A330573 a(n) = Sum_{k = 1..ceiling(n/2)} [u_2(k)*u_2(n+1-k)], where u_2(k) is number of unordered factorization k = i*j (A038548).

Table of values

List of values

A330573 a(n) = Sum_{k = 1..ceiling(n/2)} [u_2(k)u_2(n+1-k)], where u_2(k) is number of unordered factorization k = ij (A038548).

n	a(n)
0	0
1	1
2	1
3	2
4	3
5	4
6	5
7	8
8	7
9	10
10	10
11	14
12	14
13	16
14	16
15	22
16	20
17	26
18	24
19	30
20	28
21	34
22	30
23	43
24	36
25	43
26	40
27	51
28	44
29	56
30	49
31	63
32	55
33	66
34	55
35	78
36	64
37	75
38	70
39	89
40	72
41	93
42	77
43	98
44	87
45	103
46	84
47	122
48	94
49	115
50	104
51	127
52	102
53	136
54	109
55	141
56	123
57	143
58	117
59	170
60	128
61	153
62	138
63	174
64	138
65	183
66	143
67	183
68	161
69	189
70	152
71	224
72	163
73	200
74	180