A104774 - cp's OEIS frontend

A104774 a(1) = 1, a(2) = 2, a(3) = 0, a(4) = 4, and for n > 4, if n is an even number, a(n) = a(n/2) - (1 if a(n/2) is not zero), otherwise if n is an odd semiprime p*q (with q >= p), then a(n) = p+q, otherwise 0.

n	a(n)
1	1
2	2
3	0
4	4
5	0
6	0
7	0
8	3
9	6
10	0
11	0
12	0
13	0
14	0
15	8
16	2
17	0
18	5
19	0
20	0
21	10
22	0
23	0
24	0
25	10
26	0
27	0
28	0
29	0
30	7
31	0
32	1
33	14
34	0
35	12
36	4
37	0
38	0
39	16
40	0
41	0
42	9
43	0
44	0
45	0
46	0
47	0
48	0
49	14
50	9
51	20
52	0
53	0
54	0
55	16
56	0
57	22
58	0
59	0
60	6
61	0
62	0
63	0
64	0
65	18
66	13
67	0
68	0
69	26
70	11
71	0
72	3
73	0
74	0
75	0
76	0
77	18
78	15
79	0
80	0
81	0
82	0
83	0
84	8
85	22
86	0
87	32
88	0
89	0
90	0
91	20
92	0
93	34
94	0
95	24

[1, 2, 0, 4, 0, 0, 0, 3, 6, 0, 0, 0, 0, 0, 8, 2, 0, 5, 0, 0, 10, 0, 0, 0, 10, 0, 0, 0, 0, 7, 0, 1, 14, 0, 12, 4, 0, 0, 16, 0, 0, 9, 0, 0, 0, 0, 0, 0, 14, 9, 20, 0, 0, 0, 16, 0, 22, 0, 0, 6, 0, 0, 0, 0, 18, 13, 0, 0, 26, 11, 0, 3, 0, 0, 0, 0, 18, 15, 0, 0, 0, 0, 0, 8, 22, 0, 32, 0, 0, 0, 20, 0, 34, 0, 24]

cp's OEIS Frontend

A104774 a(1) = 1, a(2) = 2, a(3) = 0, a(4) = 4, and for n > 4, if n is an even number, a(n) = a(n/2) - (1 if a(n/2) is not zero), otherwise if n is an odd semiprime p*q (with q >= p), then a(n) = p+q, otherwise 0.

Table of values

List of values

n	a(n)
1	1
2	2
3	0
4	4
5	0
6	0
7	0
8	3
9	6
10	0
11	0
12	0
13	0
14	0
15	8
16	2
17	0
18	5
19	0
20	0
21	10
22	0
23	0
24	0
25	10
26	0
27	0
28	0
29	0
30	7
31	0
32	1
33	14
34	0
35	12
36	4
37	0
38	0
39	16
40	0
41	0
42	9
43	0
44	0
45	0
46	0
47	0
48	0
49	14
50	9
51	20
52	0
53	0
54	0
55	16
56	0
57	22
58	0
59	0
60	6
61	0
62	0
63	0
64	0
65	18
66	13
67	0
68	0
69	26
70	11
71	0
72	3
73	0
74	0
75	0
76	0
77	18
78	15
79	0
80	0
81	0
82	0
83	0
84	8
85	22
86	0
87	32
88	0
89	0
90	0
91	20
92	0
93	34
94	0
95	24

n	a(n)
1	1
2	2
3	0
4	4
5	0
6	0
7	0
8	3
9	6
10	0
11	0
12	0
13	0
14	0
15	8
16	2
17	0
18	5
19	0
20	0
21	10
22	0
23	0
24	0
25	10
26	0
27	0
28	0
29	0
30	7
31	0
32	1
33	14
34	0
35	12
36	4
37	0
38	0
39	16
40	0
41	0
42	9
43	0
44	0
45	0
46	0
47	0
48	0
49	14
50	9
51	20
52	0
53	0
54	0
55	16
56	0
57	22
58	0
59	0
60	6
61	0
62	0
63	0
64	0
65	18
66	13
67	0
68	0
69	26
70	11
71	0
72	3
73	0
74	0
75	0
76	0
77	18
78	15
79	0
80	0
81	0
82	0
83	0
84	8
85	22
86	0
87	32
88	0
89	0
90	0
91	20
92	0
93	34
94	0
95	24

n	a(n)
1	1
2	2
3	0
4	4
5	0
6	0
7	0
8	3
9	6
10	0
11	0
12	0
13	0
14	0
15	8
16	2
17	0
18	5
19	0
20	0
21	10
22	0
23	0
24	0
25	10
26	0
27	0
28	0
29	0
30	7
31	0
32	1
33	14
34	0
35	12
36	4
37	0
38	0
39	16
40	0
41	0
42	9
43	0
44	0
45	0
46	0
47	0
48	0
49	14
50	9
51	20
52	0
53	0
54	0
55	16
56	0
57	22
58	0
59	0
60	6
61	0
62	0
63	0
64	0
65	18
66	13
67	0
68	0
69	26
70	11
71	0
72	3
73	0
74	0
75	0
76	0
77	18
78	15
79	0
80	0
81	0
82	0
83	0
84	8
85	22
86	0
87	32
88	0
89	0
90	0
91	20
92	0
93	34
94	0
95	24