A326049 - cp's OEIS frontend

A326049 a(n) = n - A050449(n), where A050449 is the sum of divisors of the form 4k+1.

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

[0, 1, 2, 3, -1, 5, 6, 7, -1, 4, 10, 11, -1, 13, 9, 15, -1, 8, 18, 14, -1, 21, 22, 23, -6, 12, 17, 27, -1, 24, 30, 31, -1, 16, 29, 26, -1, 37, 25, 34, -1, 20, 42, 43, -15, 45, 46, 47, -1, 19, 33, 38, -1, 44, 49, 55, -1, 28, 58, 54, -1, 61, 32, 63, -19, 32, 66, 50, -1, 64, 70, 62, -1, 36, 44, 75, -1, 64, 78, 74, -10, 40]

cp's OEIS Frontend

A326049 a(n) = n - A050449(n), where A050449 is the sum of divisors of the form 4k+1.

Table of values

List of values

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

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

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