A327442 - cp's OEIS frontend

A327442 a(0) = 0; thereafter a(n) = a(n-1) + phi(n) if phi(n) > a(n-1), otherwise a(n) = a(n-1) - phi(n), where phi is the Euler phi-function A000010.

n	a(n)
0	0
1	1
2	0
3	2
4	0
5	4
6	2
7	8
8	4
9	10
10	6
11	16
12	12
13	0
14	6
15	14
16	6
17	22
18	16
19	34
20	26
21	14
22	4
23	26
24	18
25	38
26	26
27	8
28	20
29	48
30	40
31	10
32	26
33	6
34	22
35	46
36	34
37	70
38	52
39	28
40	12
41	52
42	40
43	82
44	62
45	38
46	16
47	62
48	46
49	4
50	24
51	56
52	32
53	84
54	66
55	26
56	2
57	38
58	10
59	68
60	52
61	112
62	82
63	46
64	14
65	62
66	42
67	108
68	76
69	32
70	8
71	78
72	54
73	126
74	90

[0, 1, 0, 2, 0, 4, 2, 8, 4, 10, 6, 16, 12, 0, 6, 14, 6, 22, 16, 34, 26, 14, 4, 26, 18, 38, 26, 8, 20, 48, 40, 10, 26, 6, 22, 46, 34, 70, 52, 28, 12, 52, 40, 82, 62, 38, 16, 62, 46, 4, 24, 56, 32, 84, 66, 26, 2, 38, 10, 68, 52, 112, 82, 46, 14, 62, 42, 108, 76, 32, 8, 78, 54, 126, 90]

cp's OEIS Frontend

A327442 a(0) = 0; thereafter a(n) = a(n-1) + phi(n) if phi(n) > a(n-1), otherwise a(n) = a(n-1) - phi(n), where phi is the Euler phi-function A000010.

Table of values

List of values

n	a(n)
0	0
1	1
2	0
3	2
4	0
5	4
6	2
7	8
8	4
9	10
10	6
11	16
12	12
13	0
14	6
15	14
16	6
17	22
18	16
19	34
20	26
21	14
22	4
23	26
24	18
25	38
26	26
27	8
28	20
29	48
30	40
31	10
32	26
33	6
34	22
35	46
36	34
37	70
38	52
39	28
40	12
41	52
42	40
43	82
44	62
45	38
46	16
47	62
48	46
49	4
50	24
51	56
52	32
53	84
54	66
55	26
56	2
57	38
58	10
59	68
60	52
61	112
62	82
63	46
64	14
65	62
66	42
67	108
68	76
69	32
70	8
71	78
72	54
73	126
74	90

n	a(n)
0	0
1	1
2	0
3	2
4	0
5	4
6	2
7	8
8	4
9	10
10	6
11	16
12	12
13	0
14	6
15	14
16	6
17	22
18	16
19	34
20	26
21	14
22	4
23	26
24	18
25	38
26	26
27	8
28	20
29	48
30	40
31	10
32	26
33	6
34	22
35	46
36	34
37	70
38	52
39	28
40	12
41	52
42	40
43	82
44	62
45	38
46	16
47	62
48	46
49	4
50	24
51	56
52	32
53	84
54	66
55	26
56	2
57	38
58	10
59	68
60	52
61	112
62	82
63	46
64	14
65	62
66	42
67	108
68	76
69	32
70	8
71	78
72	54
73	126
74	90

n	a(n)
0	0
1	1
2	0
3	2
4	0
5	4
6	2
7	8
8	4
9	10
10	6
11	16
12	12
13	0
14	6
15	14
16	6
17	22
18	16
19	34
20	26
21	14
22	4
23	26
24	18
25	38
26	26
27	8
28	20
29	48
30	40
31	10
32	26
33	6
34	22
35	46
36	34
37	70
38	52
39	28
40	12
41	52
42	40
43	82
44	62
45	38
46	16
47	62
48	46
49	4
50	24
51	56
52	32
53	84
54	66
55	26
56	2
57	38
58	10
59	68
60	52
61	112
62	82
63	46
64	14
65	62
66	42
67	108
68	76
69	32
70	8
71	78
72	54
73	126
74	90