A198472 - cp's OEIS frontend

A198472 a(n)=q(n) if 4 | q(n)-2, and a(n)=q(n)/2 if 4 | q(n), where q(n) is the least practical number q>n with 2(n+1)-q practical.

n	a(n)
1	2
2	2
3	2
4	6
5	6
6	4
7	4
8	6
9	6
10	8
11	6
12	18
13	8
14	18
15	8
16	18
17	18
18	10
19	10
20	12
21	12
22	14
23	12
24	30
25	14
26	30
27	14
28	30
29	30
30	16
31	16
32	18
33	18
34	20
35	18
36	42
37	20
38	42
39	20
40	42
41	42
42	54
43	24
44	24
45	28
46	54
47	24
48	28
49	30
50	54
51	28
52	32
53	54
54	28
55	28
56	30
57	30
58	32
59	30
60	66
61	32
62	66
63	32
64	66
65	66
66	78
67	36
68	36
69	40
70	78
71	36
72	40
73	42
74	78
75	40
76	44
77	78
78	40
79	40
80	42
81	42
82	44
83	42
84	90
85	44
86	90
87	44
88	90
89	90
90	52
91	48
92	48
93	50
94	50
95	48
96	52
97	50
98	54
99	50
100	56

[2, 2, 2, 6, 6, 4, 4, 6, 6, 8, 6, 18, 8, 18, 8, 18, 18, 10, 10, 12, 12, 14, 12, 30, 14, 30, 14, 30, 30, 16, 16, 18, 18, 20, 18, 42, 20, 42, 20, 42, 42, 54, 24, 24, 28, 54, 24, 28, 30, 54, 28, 32, 54, 28, 28, 30, 30, 32, 30, 66, 32, 66, 32, 66, 66, 78, 36, 36, 40, 78, 36, 40, 42, 78, 40, 44, 78, 40, 40, 42, 42, 44, 42, 90, 44, 90, 44, 90, 90, 52, 48, 48, 50, 50, 48, 52, 50, 54, 50, 56]

cp's OEIS Frontend

A198472 a(n)=q(n) if 4 | q(n)-2, and a(n)=q(n)/2 if 4 | q(n), where q(n) is the least practical number q>n with 2(n+1)-q practical.

Table of values

List of values

n	a(n)
1	2
2	2
3	2
4	6
5	6
6	4
7	4
8	6
9	6
10	8
11	6
12	18
13	8
14	18
15	8
16	18
17	18
18	10
19	10
20	12
21	12
22	14
23	12
24	30
25	14
26	30
27	14
28	30
29	30
30	16
31	16
32	18
33	18
34	20
35	18
36	42
37	20
38	42
39	20
40	42
41	42
42	54
43	24
44	24
45	28
46	54
47	24
48	28
49	30
50	54
51	28
52	32
53	54
54	28
55	28
56	30
57	30
58	32
59	30
60	66
61	32
62	66
63	32
64	66
65	66
66	78
67	36
68	36
69	40
70	78
71	36
72	40
73	42
74	78
75	40
76	44
77	78
78	40
79	40
80	42
81	42
82	44
83	42
84	90
85	44
86	90
87	44
88	90
89	90
90	52
91	48
92	48
93	50
94	50
95	48
96	52
97	50
98	54
99	50
100	56

n	a(n)
1	2
2	2
3	2
4	6
5	6
6	4
7	4
8	6
9	6
10	8
11	6
12	18
13	8
14	18
15	8
16	18
17	18
18	10
19	10
20	12
21	12
22	14
23	12
24	30
25	14
26	30
27	14
28	30
29	30
30	16
31	16
32	18
33	18
34	20
35	18
36	42
37	20
38	42
39	20
40	42
41	42
42	54
43	24
44	24
45	28
46	54
47	24
48	28
49	30
50	54
51	28
52	32
53	54
54	28
55	28
56	30
57	30
58	32
59	30
60	66
61	32
62	66
63	32
64	66
65	66
66	78
67	36
68	36
69	40
70	78
71	36
72	40
73	42
74	78
75	40
76	44
77	78
78	40
79	40
80	42
81	42
82	44
83	42
84	90
85	44
86	90
87	44
88	90
89	90
90	52
91	48
92	48
93	50
94	50
95	48
96	52
97	50
98	54
99	50
100	56

n	a(n)
1	2
2	2
3	2
4	6
5	6
6	4
7	4
8	6
9	6
10	8
11	6
12	18
13	8
14	18
15	8
16	18
17	18
18	10
19	10
20	12
21	12
22	14
23	12
24	30
25	14
26	30
27	14
28	30
29	30
30	16
31	16
32	18
33	18
34	20
35	18
36	42
37	20
38	42
39	20
40	42
41	42
42	54
43	24
44	24
45	28
46	54
47	24
48	28
49	30
50	54
51	28
52	32
53	54
54	28
55	28
56	30
57	30
58	32
59	30
60	66
61	32
62	66
63	32
64	66
65	66
66	78
67	36
68	36
69	40
70	78
71	36
72	40
73	42
74	78
75	40
76	44
77	78
78	40
79	40
80	42
81	42
82	44
83	42
84	90
85	44
86	90
87	44
88	90
89	90
90	52
91	48
92	48
93	50
94	50
95	48
96	52
97	50
98	54
99	50
100	56