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URL: https://oeis.org/A171179

⇱ A171179 - OEIS

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A171179
Numbers that are divisible by exactly 3 primes (counted with multiplicity) and sandwiched between primes.
2
12, 18, 30, 42, 102, 138, 282, 618, 642, 822, 1698, 1878, 2082, 2238, 2382, 2658, 2802, 3462, 3558, 3918, 4638, 4722, 5442, 6198, 6702, 8538, 8598, 9678, 10938, 12162, 12378, 12822, 12918, 13218, 13722, 13758, 13998, 14082, 16062, 17418, 19542
OFFSET
1,1
COMMENTS
There are 106 of these numbers below 10^5.
LINKS
EXAMPLE
12 is a term: 12 = 2*2*3, and 11 and 13 primes.
MATHEMATICA
Select[Range[9! ], Plus@@Last/@FactorInteger[ # ]==3&&PrimeQ[ #-1]&&PrimeQ[ #+1]&]
CROSSREFS
Cf. A014612.
Equals 6*A060212. - Zak Seidov and Esko Ranta, Dec 06 2009
Sequence in context: A167597 A138636 A075281 * A333869 A257768 A007371
KEYWORD
nonn
AUTHOR
STATUS
approved