A020990 - cp's OEIS frontend

A020990 a(n) = Sum_{k=0..n} (-1)^k*A020985(k).

n	a(n)
0	1
1	0
2	1
3	2
4	3
5	2
6	1
7	0
8	1
9	0
10	1
11	2
12	1
13	2
14	3
15	4
16	5
17	4
18	5
19	6
20	7
21	6
22	5
23	4
24	3
25	4
26	3
27	2
28	3
29	2
30	1
31	0
32	1
33	0
34	1
35	2
36	3
37	2
38	1
39	0
40	1
41	0
42	1
43	2
44	1
45	2
46	3
47	4
48	3
49	4
50	3
51	2
52	1
53	2
54	3
55	4
56	5
57	4
58	5
59	6
60	5
61	6
62	7
63	8
64	9
65	8
66	9
67	10
68	11
69	10
70	9
71	8
72	9
73	8
74	9
75	10
76	9
77	10
78	11

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

cp's OEIS Frontend

A020990 a(n) = Sum_{k=0..n} (-1)^k*A020985(k).

Table of values

List of values

n	a(n)
0	1
1	0
2	1
3	2
4	3
5	2
6	1
7	0
8	1
9	0
10	1
11	2
12	1
13	2
14	3
15	4
16	5
17	4
18	5
19	6
20	7
21	6
22	5
23	4
24	3
25	4
26	3
27	2
28	3
29	2
30	1
31	0
32	1
33	0
34	1
35	2
36	3
37	2
38	1
39	0
40	1
41	0
42	1
43	2
44	1
45	2
46	3
47	4
48	3
49	4
50	3
51	2
52	1
53	2
54	3
55	4
56	5
57	4
58	5
59	6
60	5
61	6
62	7
63	8
64	9
65	8
66	9
67	10
68	11
69	10
70	9
71	8
72	9
73	8
74	9
75	10
76	9
77	10
78	11

n	a(n)
0	1
1	0
2	1
3	2
4	3
5	2
6	1
7	0
8	1
9	0
10	1
11	2
12	1
13	2
14	3
15	4
16	5
17	4
18	5
19	6
20	7
21	6
22	5
23	4
24	3
25	4
26	3
27	2
28	3
29	2
30	1
31	0
32	1
33	0
34	1
35	2
36	3
37	2
38	1
39	0
40	1
41	0
42	1
43	2
44	1
45	2
46	3
47	4
48	3
49	4
50	3
51	2
52	1
53	2
54	3
55	4
56	5
57	4
58	5
59	6
60	5
61	6
62	7
63	8
64	9
65	8
66	9
67	10
68	11
69	10
70	9
71	8
72	9
73	8
74	9
75	10
76	9
77	10
78	11

n	a(n)
0	1
1	0
2	1
3	2
4	3
5	2
6	1
7	0
8	1
9	0
10	1
11	2
12	1
13	2
14	3
15	4
16	5
17	4
18	5
19	6
20	7
21	6
22	5
23	4
24	3
25	4
26	3
27	2
28	3
29	2
30	1
31	0
32	1
33	0
34	1
35	2
36	3
37	2
38	1
39	0
40	1
41	0
42	1
43	2
44	1
45	2
46	3
47	4
48	3
49	4
50	3
51	2
52	1
53	2
54	3
55	4
56	5
57	4
58	5
59	6
60	5
61	6
62	7
63	8
64	9
65	8
66	9
67	10
68	11
69	10
70	9
71	8
72	9
73	8
74	9
75	10
76	9
77	10
78	11