A076077 - cp's OEIS frontend

A076077 Group the natural numbers so that the n-th group contains n numbers, the k-th number in a group is a multiple of k and the sum of the group is prime: (2), (1, 4), (3, 8, 6), (5, 10, 12, 16), (7, 14, 9, 24, 25), ...

n	a(n)
1	2
2	1
3	4
4	3
5	8
6	6
7	5
8	10
9	12
10	16
11	7
12	14
13	9
14	24
15	25
16	11
17	18
18	15
19	20
20	45
21	30
22	13
23	22
24	21
25	28
26	35
27	36
28	42
29	17
30	26
31	27
32	32
33	40
34	48
35	49
36	72
37	19
38	34
39	33
40	44
41	50
42	54
43	56
44	80
45	63
46	23
47	38
48	39
49	52
50	55
51	60
52	70
53	64
54	90
55	110
56	29
57	46
58	51
59	68
60	65
61	66
62	77
63	88
64	81
65	120
66	132
67	31
68	58
69	57
70	76
71	75

[2, 1, 4, 3, 8, 6, 5, 10, 12, 16, 7, 14, 9, 24, 25, 11, 18, 15, 20, 45, 30, 13, 22, 21, 28, 35, 36, 42, 17, 26, 27, 32, 40, 48, 49, 72, 19, 34, 33, 44, 50, 54, 56, 80, 63, 23, 38, 39, 52, 55, 60, 70, 64, 90, 110, 29, 46, 51, 68, 65, 66, 77, 88, 81, 120, 132, 31, 58, 57, 76, 75]

cp's OEIS Frontend

A076077 Group the natural numbers so that the n-th group contains n numbers, the k-th number in a group is a multiple of k and the sum of the group is prime: (2), (1, 4), (3, 8, 6), (5, 10, 12, 16), (7, 14, 9, 24, 25), ...

Table of values

List of values

n	a(n)
1	2
2	1
3	4
4	3
5	8
6	6
7	5
8	10
9	12
10	16
11	7
12	14
13	9
14	24
15	25
16	11
17	18
18	15
19	20
20	45
21	30
22	13
23	22
24	21
25	28
26	35
27	36
28	42
29	17
30	26
31	27
32	32
33	40
34	48
35	49
36	72
37	19
38	34
39	33
40	44
41	50
42	54
43	56
44	80
45	63
46	23
47	38
48	39
49	52
50	55
51	60
52	70
53	64
54	90
55	110
56	29
57	46
58	51
59	68
60	65
61	66
62	77
63	88
64	81
65	120
66	132
67	31
68	58
69	57
70	76
71	75

n	a(n)
1	2
2	1
3	4
4	3
5	8
6	6
7	5
8	10
9	12
10	16
11	7
12	14
13	9
14	24
15	25
16	11
17	18
18	15
19	20
20	45
21	30
22	13
23	22
24	21
25	28
26	35
27	36
28	42
29	17
30	26
31	27
32	32
33	40
34	48
35	49
36	72
37	19
38	34
39	33
40	44
41	50
42	54
43	56
44	80
45	63
46	23
47	38
48	39
49	52
50	55
51	60
52	70
53	64
54	90
55	110
56	29
57	46
58	51
59	68
60	65
61	66
62	77
63	88
64	81
65	120
66	132
67	31
68	58
69	57
70	76
71	75

n	a(n)
1	2
2	1
3	4
4	3
5	8
6	6
7	5
8	10
9	12
10	16
11	7
12	14
13	9
14	24
15	25
16	11
17	18
18	15
19	20
20	45
21	30
22	13
23	22
24	21
25	28
26	35
27	36
28	42
29	17
30	26
31	27
32	32
33	40
34	48
35	49
36	72
37	19
38	34
39	33
40	44
41	50
42	54
43	56
44	80
45	63
46	23
47	38
48	39
49	52
50	55
51	60
52	70
53	64
54	90
55	110
56	29
57	46
58	51
59	68
60	65
61	66
62	77
63	88
64	81
65	120
66	132
67	31
68	58
69	57
70	76
71	75