A328638 - cp's OEIS frontend

A328638 a(n) is the sum of m such that 2 <= m <= n and gpf(m) = gpf(n), where gpf(i) is the greatest prime factor of i (A006530), with a(1) = 1.

n	a(n)
1	1
2	2
3	3
4	6
5	5
6	9
7	7
8	14
9	18
10	15
11	11
12	30
13	13
14	21
15	30
16	30
17	17
18	48
19	19
20	50
21	42
22	33
23	23
24	72
25	75
26	39
27	99
28	70
29	29
30	105
31	31
32	62
33	66
34	51
35	105
36	135
37	37
38	57
39	78
40	145
41	41
42	147
43	43
44	110
45	190
46	69
47	47
48	183
49	196
50	240
51	102
52	130
53	53
54	237
55	165
56	252
57	114
58	87
59	59
60	300

[1, 2, 3, 6, 5, 9, 7, 14, 18, 15, 11, 30, 13, 21, 30, 30, 17, 48, 19, 50, 42, 33, 23, 72, 75, 39, 99, 70, 29, 105, 31, 62, 66, 51, 105, 135, 37, 57, 78, 145, 41, 147, 43, 110, 190, 69, 47, 183, 196, 240, 102, 130, 53, 237, 165, 252, 114, 87, 59, 300]

cp's OEIS Frontend

A328638 a(n) is the sum of m such that 2 <= m <= n and gpf(m) = gpf(n), where gpf(i) is the greatest prime factor of i (A006530), with a(1) = 1.

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	6
5	5
6	9
7	7
8	14
9	18
10	15
11	11
12	30
13	13
14	21
15	30
16	30
17	17
18	48
19	19
20	50
21	42
22	33
23	23
24	72
25	75
26	39
27	99
28	70
29	29
30	105
31	31
32	62
33	66
34	51
35	105
36	135
37	37
38	57
39	78
40	145
41	41
42	147
43	43
44	110
45	190
46	69
47	47
48	183
49	196
50	240
51	102
52	130
53	53
54	237
55	165
56	252
57	114
58	87
59	59
60	300

n	a(n)
1	1
2	2
3	3
4	6
5	5
6	9
7	7
8	14
9	18
10	15
11	11
12	30
13	13
14	21
15	30
16	30
17	17
18	48
19	19
20	50
21	42
22	33
23	23
24	72
25	75
26	39
27	99
28	70
29	29
30	105
31	31
32	62
33	66
34	51
35	105
36	135
37	37
38	57
39	78
40	145
41	41
42	147
43	43
44	110
45	190
46	69
47	47
48	183
49	196
50	240
51	102
52	130
53	53
54	237
55	165
56	252
57	114
58	87
59	59
60	300

n	a(n)
1	1
2	2
3	3
4	6
5	5
6	9
7	7
8	14
9	18
10	15
11	11
12	30
13	13
14	21
15	30
16	30
17	17
18	48
19	19
20	50
21	42
22	33
23	23
24	72
25	75
26	39
27	99
28	70
29	29
30	105
31	31
32	62
33	66
34	51
35	105
36	135
37	37
38	57
39	78
40	145
41	41
42	147
43	43
44	110
45	190
46	69
47	47
48	183
49	196
50	240
51	102
52	130
53	53
54	237
55	165
56	252
57	114
58	87
59	59
60	300