A145031 Smallest odd n-almost prime m such that m-2 and m+2 are both prime (cousin primes).
5, 9, 45, 81, 675, 1215, 14175, 28431, 72171, 597051, 2679075, 885735, 10333575, 89813529, 286446699, 390609135, 789189885, 7274895849, 55142849601, 204945438681, 154580775111, 1049522104701, 596240132571, 1307544150375
Offset: 1
Keywords
Examples
a(5) = 675 = 3^3*5^2 is a 5-almost prime and 675-2 and 675+2 are both prime (cousin primes). 675 is the smallest such 5-almost prime.
Links
- Donovan Johnson, Table of n, a(n) for n=1..203