A222580 - cp's OEIS frontend

A222580 Number of ways to write n=p_m-p_{m-1}+...+(-1)^{m-k}p_k with k and p_m<=3n, and p_m+1 and p_k-1 both practical, where p_j denotes the j-th prime.

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

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

cp's OEIS Frontend

A222580 Number of ways to write n=p_m-p_{m-1}+...+(-1)^{m-k}p_k with k and p_m<=3n, and p_m+1 and p_k-1 both practical, where p_j denotes the j-th prime.

Table of values

List of values

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

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

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