A059764 - cp's OEIS frontend

A059764 Initial (unsafe) primes of Cunningham chains of first type with length exactly 5. Primes in A059453 that survive as primes just four "2p+1 iterations", forming chains of exactly 5 terms.

n	a(n)
1	2
2	53639
3	53849
4	61409
5	66749
6	143609
7	167729
8	186149
9	206369
10	268049
11	296099
12	340919
13	422069
14	446609
15	539009
16	594449
17	607319
18	658349
19	671249
20	725009
21	775949
22	812849
23	819509
24	926669
25	1008209
26	1092089
27	1132949
28	1271849

[2, 53639, 53849, 61409, 66749, 143609, 167729, 186149, 206369, 268049, 296099, 340919, 422069, 446609, 539009, 594449, 607319, 658349, 671249, 725009, 775949, 812849, 819509, 926669, 1008209, 1092089, 1132949, 1271849]

cp's OEIS Frontend

A059764 Initial (unsafe) primes of Cunningham chains of first type with length exactly 5. Primes in A059453 that survive as primes just four "2p+1 iterations", forming chains of exactly 5 terms.

Table of values

List of values