A140199 - cp's OEIS frontend

A140199 a(n) = the number of pairs of (not necessarily distinct) positive integers j and k where j <= n and k <= n such that k+j is prime.

n	a(n)
1	1
2	2
3	3
4	5
5	6
6	8
7	10
8	12
9	15
10	19
11	22
12	26
13	29
14	32
15	36
16	41
17	45
18	49
19	53
20	57
21	62
22	68
23	73
24	79
25	85
26	91
27	98
28	105
29	111
30	118
31	125
32	132
33	139
34	147
35	155
36	164
37	173
38	182
39	191
40	201
41	210
42	220
43	229
44	238
45	248
46	258
47	267
48	276
49	286
50	296
51	307
52	319
53	330
54	342
55	355
56	368
57	382
58	396
59	409
60	422

[1, 2, 3, 5, 6, 8, 10, 12, 15, 19, 22, 26, 29, 32, 36, 41, 45, 49, 53, 57, 62, 68, 73, 79, 85, 91, 98, 105, 111, 118, 125, 132, 139, 147, 155, 164, 173, 182, 191, 201, 210, 220, 229, 238, 248, 258, 267, 276, 286, 296, 307, 319, 330, 342, 355, 368, 382, 396, 409, 422]

cp's OEIS Frontend

A140199 a(n) = the number of pairs of (not necessarily distinct) positive integers j and k where j <= n and k <= n such that k+j is prime.

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	5
5	6
6	8
7	10
8	12
9	15
10	19
11	22
12	26
13	29
14	32
15	36
16	41
17	45
18	49
19	53
20	57
21	62
22	68
23	73
24	79
25	85
26	91
27	98
28	105
29	111
30	118
31	125
32	132
33	139
34	147
35	155
36	164
37	173
38	182
39	191
40	201
41	210
42	220
43	229
44	238
45	248
46	258
47	267
48	276
49	286
50	296
51	307
52	319
53	330
54	342
55	355
56	368
57	382
58	396
59	409
60	422

n	a(n)
1	1
2	2
3	3
4	5
5	6
6	8
7	10
8	12
9	15
10	19
11	22
12	26
13	29
14	32
15	36
16	41
17	45
18	49
19	53
20	57
21	62
22	68
23	73
24	79
25	85
26	91
27	98
28	105
29	111
30	118
31	125
32	132
33	139
34	147
35	155
36	164
37	173
38	182
39	191
40	201
41	210
42	220
43	229
44	238
45	248
46	258
47	267
48	276
49	286
50	296
51	307
52	319
53	330
54	342
55	355
56	368
57	382
58	396
59	409
60	422

n	a(n)
1	1
2	2
3	3
4	5
5	6
6	8
7	10
8	12
9	15
10	19
11	22
12	26
13	29
14	32
15	36
16	41
17	45
18	49
19	53
20	57
21	62
22	68
23	73
24	79
25	85
26	91
27	98
28	105
29	111
30	118
31	125
32	132
33	139
34	147
35	155
36	164
37	173
38	182
39	191
40	201
41	210
42	220
43	229
44	238
45	248
46	258
47	267
48	276
49	286
50	296
51	307
52	319
53	330
54	342
55	355
56	368
57	382
58	396
59	409
60	422