A138921 - cp's OEIS frontend

A138921 Indices k such that A020508(k)=Phi[k](-9) is prime, where Phi is a cyclotomic polynomial.

n	a(n)
1	3
2	9
3	12
4	15
5	20
6	27
7	33
8	36
9	59
10	69
11	91
12	152
13	207
14	223
15	232
16	264
17	336
18	340
19	380
20	381
21	492
22	533
23	540
24	547
25	549
26	585
27	615
28	624
29	627
30	720
31	773
32	1009
33	1287
34	1320
35	1428
36	1537
37	1823
38	2093
39	2401
40	2724
41	2733
42	2804
43	2920
44	3316
45	3803
46	4124
47	4132
48	4620
49	7143
50	7520
51	7708

[3, 9, 12, 15, 20, 27, 33, 36, 59, 69, 91, 152, 207, 223, 232, 264, 336, 340, 380, 381, 492, 533, 540, 547, 549, 585, 615, 624, 627, 720, 773, 1009, 1287, 1320, 1428, 1537, 1823, 2093, 2401, 2724, 2733, 2804, 2920, 3316, 3803, 4124, 4132, 4620, 7143, 7520, 7708]

cp's OEIS Frontend

A138921 Indices k such that A020508(k)=Phi[k](-9) is prime, where Phi is a cyclotomic polynomial.

Table of values

List of values