A105673 - cp's OEIS frontend

A105673 One-half of theta series of square lattice (or half the number of ways of writing n > 0 as a sum of 2 squares), without the constant term, which is 1/2.

n	a(n)
1	2
2	2
3	0
4	2
5	4
6	0
7	0
8	2
9	2
10	4
11	0
12	0
13	4
14	0
15	0
16	2
17	4
18	2
19	0
20	4
21	0
22	0
23	0
24	0
25	6
26	4
27	0
28	0
29	4
30	0
31	0
32	2
33	0
34	4
35	0
36	2
37	4
38	0
39	0
40	4
41	4
42	0
43	0
44	0
45	4
46	0
47	0
48	0
49	2
50	6
51	0
52	4
53	4
54	0
55	0
56	0
57	0
58	4
59	0
60	0
61	4
62	0
63	0
64	2
65	8
66	0
67	0
68	4
69	0
70	0
71	0
72	2
73	4
74	4
75	0
76	0
77	0
78	0
79	0
80	4
81	2
82	4
83	0
84	0
85	8
86	0
87	0
88	0
89	4
90	4
91	0
92	0
93	0
94	0
95	0
96	0
97	4
98	2
99	0

[2, 2, 0, 2, 4, 0, 0, 2, 2, 4, 0, 0, 4, 0, 0, 2, 4, 2, 0, 4, 0, 0, 0, 0, 6, 4, 0, 0, 4, 0, 0, 2, 0, 4, 0, 2, 4, 0, 0, 4, 4, 0, 0, 0, 4, 0, 0, 0, 2, 6, 0, 4, 4, 0, 0, 0, 0, 4, 0, 0, 4, 0, 0, 2, 8, 0, 0, 4, 0, 0, 0, 2, 4, 4, 0, 0, 0, 0, 0, 4, 2, 4, 0, 0, 8, 0, 0, 0, 4, 4, 0, 0, 0, 0, 0, 0, 4, 2, 0]

cp's OEIS Frontend

A105673 One-half of theta series of square lattice (or half the number of ways of writing n > 0 as a sum of 2 squares), without the constant term, which is 1/2.

Table of values

List of values

n	a(n)
1	2
2	2
3	0
4	2
5	4
6	0
7	0
8	2
9	2
10	4
11	0
12	0
13	4
14	0
15	0
16	2
17	4
18	2
19	0
20	4
21	0
22	0
23	0
24	0
25	6
26	4
27	0
28	0
29	4
30	0
31	0
32	2
33	0
34	4
35	0
36	2
37	4
38	0
39	0
40	4
41	4
42	0
43	0
44	0
45	4
46	0
47	0
48	0
49	2
50	6
51	0
52	4
53	4
54	0
55	0
56	0
57	0
58	4
59	0
60	0
61	4
62	0
63	0
64	2
65	8
66	0
67	0
68	4
69	0
70	0
71	0
72	2
73	4
74	4
75	0
76	0
77	0
78	0
79	0
80	4
81	2
82	4
83	0
84	0
85	8
86	0
87	0
88	0
89	4
90	4
91	0
92	0
93	0
94	0
95	0
96	0
97	4
98	2
99	0

n	a(n)
1	2
2	2
3	0
4	2
5	4
6	0
7	0
8	2
9	2
10	4
11	0
12	0
13	4
14	0
15	0
16	2
17	4
18	2
19	0
20	4
21	0
22	0
23	0
24	0
25	6
26	4
27	0
28	0
29	4
30	0
31	0
32	2
33	0
34	4
35	0
36	2
37	4
38	0
39	0
40	4
41	4
42	0
43	0
44	0
45	4
46	0
47	0
48	0
49	2
50	6
51	0
52	4
53	4
54	0
55	0
56	0
57	0
58	4
59	0
60	0
61	4
62	0
63	0
64	2
65	8
66	0
67	0
68	4
69	0
70	0
71	0
72	2
73	4
74	4
75	0
76	0
77	0
78	0
79	0
80	4
81	2
82	4
83	0
84	0
85	8
86	0
87	0
88	0
89	4
90	4
91	0
92	0
93	0
94	0
95	0
96	0
97	4
98	2
99	0

n	a(n)
1	2
2	2
3	0
4	2
5	4
6	0
7	0
8	2
9	2
10	4
11	0
12	0
13	4
14	0
15	0
16	2
17	4
18	2
19	0
20	4
21	0
22	0
23	0
24	0
25	6
26	4
27	0
28	0
29	4
30	0
31	0
32	2
33	0
34	4
35	0
36	2
37	4
38	0
39	0
40	4
41	4
42	0
43	0
44	0
45	4
46	0
47	0
48	0
49	2
50	6
51	0
52	4
53	4
54	0
55	0
56	0
57	0
58	4
59	0
60	0
61	4
62	0
63	0
64	2
65	8
66	0
67	0
68	4
69	0
70	0
71	0
72	2
73	4
74	4
75	0
76	0
77	0
78	0
79	0
80	4
81	2
82	4
83	0
84	0
85	8
86	0
87	0
88	0
89	4
90	4
91	0
92	0
93	0
94	0
95	0
96	0
97	4
98	2
99	0