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A145031
Smallest odd n-almost prime m such that m-2 and m+2 are both prime (cousin primes).
1
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
1,1
LINKS
EXAMPLE
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.
CROSSREFS
KEYWORD
nonn
AUTHOR
Donovan Johnson, Sep 30 2008
STATUS
approved