A290947 - cp's OEIS frontend

A290947 Primes p1 > 3, such that p2 = 3p1-2 and p3 = (p1p2+1)/2 are also primes, so p1p2*p3 is a triangular 3-Carmichael number.

n	a(n)
1	7
2	13
3	37
4	43
5	61
6	193
7	211
8	271
9	307
10	331
11	601
12	673
13	727
14	757
15	823
16	1063
17	1297
18	1447
19	1597
20	1621
21	1657
22	1693
23	2113
24	2281
25	2347
26	2437
27	2503
28	3001
29	3067
30	3271
31	3733
32	4093
33	4201
34	4957
35	5581
36	6073
37	6607
38	7321
39	7333
40	7723
41	7867
42	8287
43	8581
44	8647
45	9643
46	10243

[7, 13, 37, 43, 61, 193, 211, 271, 307, 331, 601, 673, 727, 757, 823, 1063, 1297, 1447, 1597, 1621, 1657, 1693, 2113, 2281, 2347, 2437, 2503, 3001, 3067, 3271, 3733, 4093, 4201, 4957, 5581, 6073, 6607, 7321, 7333, 7723, 7867, 8287, 8581, 8647, 9643, 10243]

cp's OEIS Frontend

A290947 Primes p1 > 3, such that p2 = 3p1-2 and p3 = (p1p2+1)/2 are also primes, so p1p2*p3 is a triangular 3-Carmichael number.

Table of values

List of values

cp's OEIS Frontend

A290947 Primes p1 > 3, such that p2 = 3p1-2 and p3 = (p1*p2+1)/2 are also primes, so p1*p2*p3 is a triangular 3-Carmichael number.

Table of values

List of values

A290947 Primes p1 > 3, such that p2 = 3p1-2 and p3 = (p1p2+1)/2 are also primes, so p1p2*p3 is a triangular 3-Carmichael number.