A174214 - cp's OEIS frontend

A174214 a(n) = a(n-1)+1, if the previous term a(n-1) and n-1-(-1)^n are coprime, else a(n)=2*n-4.

n	a(n)
9	14
10	16
11	17
12	18
13	19
14	20
15	26
16	28
17	29
18	30
19	31
20	32
21	33
22	34
23	35
24	36
25	37
26	38
27	39
28	52
29	53
30	54
31	55
32	60
33	62
34	64
35	65
36	66
37	67
38	68
39	69
40	70
41	71
42	72
43	73
44	74
45	75
46	76
47	77
48	78
49	79
50	80
51	81
52	82
53	83
54	84
55	85
56	86
57	87
58	88
59	89
60	90
61	91
62	92
63	93
64	124
65	125
66	126
67	127
68	128
69	129
70	130
71	131
72	132
73	133
74	134

[14, 16, 17, 18, 19, 20, 26, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 52, 53, 54, 55, 60, 62, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134]

cp's OEIS Frontend

A174214 a(n) = a(n-1)+1, if the previous term a(n-1) and n-1-(-1)^n are coprime, else a(n)=2*n-4.

Table of values

List of values

n	a(n)
9	14
10	16
11	17
12	18
13	19
14	20
15	26
16	28
17	29
18	30
19	31
20	32
21	33
22	34
23	35
24	36
25	37
26	38
27	39
28	52
29	53
30	54
31	55
32	60
33	62
34	64
35	65
36	66
37	67
38	68
39	69
40	70
41	71
42	72
43	73
44	74
45	75
46	76
47	77
48	78
49	79
50	80
51	81
52	82
53	83
54	84
55	85
56	86
57	87
58	88
59	89
60	90
61	91
62	92
63	93
64	124
65	125
66	126
67	127
68	128
69	129
70	130
71	131
72	132
73	133
74	134

n	a(n)
9	14
10	16
11	17
12	18
13	19
14	20
15	26
16	28
17	29
18	30
19	31
20	32
21	33
22	34
23	35
24	36
25	37
26	38
27	39
28	52
29	53
30	54
31	55
32	60
33	62
34	64
35	65
36	66
37	67
38	68
39	69
40	70
41	71
42	72
43	73
44	74
45	75
46	76
47	77
48	78
49	79
50	80
51	81
52	82
53	83
54	84
55	85
56	86
57	87
58	88
59	89
60	90
61	91
62	92
63	93
64	124
65	125
66	126
67	127
68	128
69	129
70	130
71	131
72	132
73	133
74	134

n	a(n)
9	14
10	16
11	17
12	18
13	19
14	20
15	26
16	28
17	29
18	30
19	31
20	32
21	33
22	34
23	35
24	36
25	37
26	38
27	39
28	52
29	53
30	54
31	55
32	60
33	62
34	64
35	65
36	66
37	67
38	68
39	69
40	70
41	71
42	72
43	73
44	74
45	75
46	76
47	77
48	78
49	79
50	80
51	81
52	82
53	83
54	84
55	85
56	86
57	87
58	88
59	89
60	90
61	91
62	92
63	93
64	124
65	125
66	126
67	127
68	128
69	129
70	130
71	131
72	132
73	133
74	134