A212496 - cp's OEIS frontend

A212496 a(n) = Sum_{k=1..n} (-1)^(k-Omega(k)) with Omega(k) the total number of prime factors of k (counted with multiplicity).

n	a(n)
1	-1
2	-2
3	-1
4	0
5	1
6	2
7	3
8	2
9	1
10	2
11	3
12	2
13	3
14	4
15	3
16	4
17	5
18	4
19	5
20	4
21	3
22	4
23	5
24	6
25	5
26	6
27	7
28	6
29	7
30	6
31	7
32	6
33	5
34	6
35	5
36	6
37	7
38	8
39	7
40	8
41	9
42	8
43	9
44	8
45	9
46	10
47	11
48	10
49	9
50	8
51	7
52	6
53	7
54	8
55	7
56	8
57	7
58	8
59	9
60	10

[-1, -2, -1, 0, 1, 2, 3, 2, 1, 2, 3, 2, 3, 4, 3, 4, 5, 4, 5, 4, 3, 4, 5, 6, 5, 6, 7, 6, 7, 6, 7, 6, 5, 6, 5, 6, 7, 8, 7, 8, 9, 8, 9, 8, 9, 10, 11, 10, 9, 8, 7, 6, 7, 8, 7, 8, 7, 8, 9, 10]

cp's OEIS Frontend

A212496 a(n) = Sum_{k=1..n} (-1)^(k-Omega(k)) with Omega(k) the total number of prime factors of k (counted with multiplicity).

Table of values

List of values

n	a(n)
1	-1
2	-2
3	-1
4	0
5	1
6	2
7	3
8	2
9	1
10	2
11	3
12	2
13	3
14	4
15	3
16	4
17	5
18	4
19	5
20	4
21	3
22	4
23	5
24	6
25	5
26	6
27	7
28	6
29	7
30	6
31	7
32	6
33	5
34	6
35	5
36	6
37	7
38	8
39	7
40	8
41	9
42	8
43	9
44	8
45	9
46	10
47	11
48	10
49	9
50	8
51	7
52	6
53	7
54	8
55	7
56	8
57	7
58	8
59	9
60	10

n	a(n)
1	-1
2	-2
3	-1
4	0
5	1
6	2
7	3
8	2
9	1
10	2
11	3
12	2
13	3
14	4
15	3
16	4
17	5
18	4
19	5
20	4
21	3
22	4
23	5
24	6
25	5
26	6
27	7
28	6
29	7
30	6
31	7
32	6
33	5
34	6
35	5
36	6
37	7
38	8
39	7
40	8
41	9
42	8
43	9
44	8
45	9
46	10
47	11
48	10
49	9
50	8
51	7
52	6
53	7
54	8
55	7
56	8
57	7
58	8
59	9
60	10

n	a(n)
1	-1
2	-2
3	-1
4	0
5	1
6	2
7	3
8	2
9	1
10	2
11	3
12	2
13	3
14	4
15	3
16	4
17	5
18	4
19	5
20	4
21	3
22	4
23	5
24	6
25	5
26	6
27	7
28	6
29	7
30	6
31	7
32	6
33	5
34	6
35	5
36	6
37	7
38	8
39	7
40	8
41	9
42	8
43	9
44	8
45	9
46	10
47	11
48	10
49	9
50	8
51	7
52	6
53	7
54	8
55	7
56	8
57	7
58	8
59	9
60	10