A213325 - cp's OEIS frontend

A213325 Number of ways to write n = q + sum_{k=1}^m(-1)^{m-k}p_k, where p_k is the k-th prime, and q is a practical number with q-4 and q+4 also practical.

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	1
10	1
11	1
12	1
13	2
14	1
15	2
16	2
17	2
18	1
19	2
20	3
21	3
22	1
23	2
24	4
25	3
26	2
27	3
28	4
29	4
30	3
31	3
32	4
33	4
34	4
35	4
36	4
37	5
38	4
39	4
40	5
41	5
42	3
43	3
44	4
45	4
46	4
47	3
48	4
49	4
50	4
51	3
52	4
53	4
54	4
55	3
56	3
57	5
58	3
59	2
60	4
61	6
62	4
63	3
64	6
65	7
66	2
67	2
68	6
69	6
70	2
71	2
72	5
73	7
74	2
75	2
76	5
77	6
78	3
79	3
80	3
81	7
82	3
83	2
84	3
85	7
86	4
87	5
88	4
89	8
90	2
91	5
92	4
93	6
94	2
95	4
96	2
97	5
98	3
99	5
100	4

[0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 1, 2, 2, 2, 1, 2, 3, 3, 1, 2, 4, 3, 2, 3, 4, 4, 3, 3, 4, 4, 4, 4, 4, 5, 4, 4, 5, 5, 3, 3, 4, 4, 4, 3, 4, 4, 4, 3, 4, 4, 4, 3, 3, 5, 3, 2, 4, 6, 4, 3, 6, 7, 2, 2, 6, 6, 2, 2, 5, 7, 2, 2, 5, 6, 3, 3, 3, 7, 3, 2, 3, 7, 4, 5, 4, 8, 2, 5, 4, 6, 2, 4, 2, 5, 3, 5, 4]

cp's OEIS Frontend

A213325 Number of ways to write n = q + sum_{k=1}^m(-1)^{m-k}p_k, where p_k is the k-th prime, and q is a practical number with q-4 and q+4 also practical.

Table of values

List of values

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	1
10	1
11	1
12	1
13	2
14	1
15	2
16	2
17	2
18	1
19	2
20	3
21	3
22	1
23	2
24	4
25	3
26	2
27	3
28	4
29	4
30	3
31	3
32	4
33	4
34	4
35	4
36	4
37	5
38	4
39	4
40	5
41	5
42	3
43	3
44	4
45	4
46	4
47	3
48	4
49	4
50	4
51	3
52	4
53	4
54	4
55	3
56	3
57	5
58	3
59	2
60	4
61	6
62	4
63	3
64	6
65	7
66	2
67	2
68	6
69	6
70	2
71	2
72	5
73	7
74	2
75	2
76	5
77	6
78	3
79	3
80	3
81	7
82	3
83	2
84	3
85	7
86	4
87	5
88	4
89	8
90	2
91	5
92	4
93	6
94	2
95	4
96	2
97	5
98	3
99	5
100	4

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	1
10	1
11	1
12	1
13	2
14	1
15	2
16	2
17	2
18	1
19	2
20	3
21	3
22	1
23	2
24	4
25	3
26	2
27	3
28	4
29	4
30	3
31	3
32	4
33	4
34	4
35	4
36	4
37	5
38	4
39	4
40	5
41	5
42	3
43	3
44	4
45	4
46	4
47	3
48	4
49	4
50	4
51	3
52	4
53	4
54	4
55	3
56	3
57	5
58	3
59	2
60	4
61	6
62	4
63	3
64	6
65	7
66	2
67	2
68	6
69	6
70	2
71	2
72	5
73	7
74	2
75	2
76	5
77	6
78	3
79	3
80	3
81	7
82	3
83	2
84	3
85	7
86	4
87	5
88	4
89	8
90	2
91	5
92	4
93	6
94	2
95	4
96	2
97	5
98	3
99	5
100	4

n	a(n)
1	0
2	0
3	0
4	0
5	0
6	0
7	0
8	0
9	1
10	1
11	1
12	1
13	2
14	1
15	2
16	2
17	2
18	1
19	2
20	3
21	3
22	1
23	2
24	4
25	3
26	2
27	3
28	4
29	4
30	3
31	3
32	4
33	4
34	4
35	4
36	4
37	5
38	4
39	4
40	5
41	5
42	3
43	3
44	4
45	4
46	4
47	3
48	4
49	4
50	4
51	3
52	4
53	4
54	4
55	3
56	3
57	5
58	3
59	2
60	4
61	6
62	4
63	3
64	6
65	7
66	2
67	2
68	6
69	6
70	2
71	2
72	5
73	7
74	2
75	2
76	5
77	6
78	3
79	3
80	3
81	7
82	3
83	2
84	3
85	7
86	4
87	5
88	4
89	8
90	2
91	5
92	4
93	6
94	2
95	4
96	2
97	5
98	3
99	5
100	4