A118469 - cp's OEIS frontend

A118469 Triangle read by rows: a(n,m) = If(n = 1, then 1, else Prime(n) - 1 + Sum_{k=n..m} (Prime(k + 1) - Prime(k))/2 ).

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

[1, 1, 3, 1, 4, 5, 1, 6, 7, 8, 1, 7, 8, 9, 11, 1, 9, 10, 11, 13, 14, 1, 10, 11, 12, 14, 15, 17, 1, 12, 13, 14, 16, 17, 19, 20, 1, 15, 16, 17, 19, 20, 22, 23, 25, 1, 16, 17, 18, 20, 21, 23, 24, 26, 29, 1, 19, 20, 21, 23, 24, 26, 27, 29, 32, 33, 1, 21, 22, 23, 25, 26, 28, 29, 31, 34, 35]

cp's OEIS Frontend

A118469 Triangle read by rows: a(n,m) = If(n = 1, then 1, else Prime(n) - 1 + Sum_{k=n..m} (Prime(k + 1) - Prime(k))/2 ).

Table of values

List of values

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

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

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