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

1,1

Links

Donovan Johnson, Table of n, a(n) for n=1..203

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

Cf. A023200, A046132, A068525.

Sequence in context: A321718 A304127 A220518 * A121724 A149496 A149497

Adjacent sequences: A145028 A145029 A145030 * A145032 A145033 A145034

Keyword

nonn

Author

Donovan Johnson, Sep 30 2008

Status

approved