A380483 - cp's OEIS frontend

A380483 a(n) = least k such that A010846(6*prime(k)) = n, or -1 if no solution exists.

n	a(n)
18	3
19	4
20	-1
21	-1
22	5
23	6
24	-1
25	7
26	8
27	9
28	-1
29	10
30	-1
31	12
32	13
33	14
34	16
35	17
36	19
37	21
38	23
39	24
40	25
41	29
42	31
43	32
44	35
45	38
46	40
47	44
48	48
49	54
50	55
51	62
52	67
53	69
54	73
55	77
56	84
57	93
58	98
59	106
60	119
61	124
62	130
63	136
64	151
65	165
66	173
67	184
68	191
69	211
70	219
71	232
72	243
73	270
74	296
75	310
76	328
77	343
78	378
79	399
80	422

[3, 4, -1, -1, 5, 6, -1, 7, 8, 9, -1, 10, -1, 12, 13, 14, 16, 17, 19, 21, 23, 24, 25, 29, 31, 32, 35, 38, 40, 44, 48, 54, 55, 62, 67, 69, 73, 77, 84, 93, 98, 106, 119, 124, 130, 136, 151, 165, 173, 184, 191, 211, 219, 232, 243, 270, 296, 310, 328, 343, 378, 399, 422]

cp's OEIS Frontend

A380483 a(n) = least k such that A010846(6*prime(k)) = n, or -1 if no solution exists.

Table of values

List of values

n	a(n)
18	3
19	4
20	-1
21	-1
22	5
23	6
24	-1
25	7
26	8
27	9
28	-1
29	10
30	-1
31	12
32	13
33	14
34	16
35	17
36	19
37	21
38	23
39	24
40	25
41	29
42	31
43	32
44	35
45	38
46	40
47	44
48	48
49	54
50	55
51	62
52	67
53	69
54	73
55	77
56	84
57	93
58	98
59	106
60	119
61	124
62	130
63	136
64	151
65	165
66	173
67	184
68	191
69	211
70	219
71	232
72	243
73	270
74	296
75	310
76	328
77	343
78	378
79	399
80	422

n	a(n)
18	3
19	4
20	-1
21	-1
22	5
23	6
24	-1
25	7
26	8
27	9
28	-1
29	10
30	-1
31	12
32	13
33	14
34	16
35	17
36	19
37	21
38	23
39	24
40	25
41	29
42	31
43	32
44	35
45	38
46	40
47	44
48	48
49	54
50	55
51	62
52	67
53	69
54	73
55	77
56	84
57	93
58	98
59	106
60	119
61	124
62	130
63	136
64	151
65	165
66	173
67	184
68	191
69	211
70	219
71	232
72	243
73	270
74	296
75	310
76	328
77	343
78	378
79	399
80	422

n	a(n)
18	3
19	4
20	-1
21	-1
22	5
23	6
24	-1
25	7
26	8
27	9
28	-1
29	10
30	-1
31	12
32	13
33	14
34	16
35	17
36	19
37	21
38	23
39	24
40	25
41	29
42	31
43	32
44	35
45	38
46	40
47	44
48	48
49	54
50	55
51	62
52	67
53	69
54	73
55	77
56	84
57	93
58	98
59	106
60	119
61	124
62	130
63	136
64	151
65	165
66	173
67	184
68	191
69	211
70	219
71	232
72	243
73	270
74	296
75	310
76	328
77	343
78	378
79	399
80	422