A323741 - cp's OEIS frontend

A323741 a(n) = m-p where m = (2n+1)^2 and p is the largest prime < m.

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

[2, 2, 2, 2, 8, 2, 2, 6, 2, 2, 6, 6, 2, 2, 8, 2, 2, 2, 10, 12, 2, 8, 2, 2, 8, 6, 2, 20, 12, 2, 2, 6, 6, 2, 2, 6, 2, 2, 12, 8, 6, 6, 8, 2, 8, 2, 12, 6, 10, 8, 2, 22, 2, 14, 20, 6, 6, 2, 2, 2, 8, 6, 2, 8, 2, 6, 2, 12, 2, 14, 6, 2, 8, 8, 14, 10, 2, 18, 20, 2, 8, 14, 6, 2, 10, 2, 32, 2, 12, 12, 2, 8, 6, 44, 2, 6, 14, 6, 20, 14]

cp's OEIS Frontend

A323741 a(n) = m-p where m = (2n+1)^2 and p is the largest prime < m.

Table of values

List of values

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

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

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