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A101937
Numbers n with omega(n) > omega of 2 nearest larger and 2 nearest smaller neighbors.
2
6, 30, 42, 60, 66, 70, 78, 84, 90, 102, 105, 110, 114, 120, 126, 150, 165, 174, 186, 190, 195, 198, 204, 210, 234, 246, 252, 255, 270, 273, 276, 290, 294, 300, 315, 318, 322, 330, 336, 345, 354, 357, 360, 385, 390, 396, 399, 402, 414, 420
OFFSET
1,1
COMMENTS
Prime factors counted without multiplicity. - Harvey P. Dale, Dec 17 2014
LINKS
EXAMPLE
150 is in the sequence because it has three unique prime factors (2,3 and 5), whereas 148, 149, 151 and 152 each have fewer.
MATHEMATICA
For[i=2, i<1000, If[And[Length[FactorInteger[i-2]]<Length[FactorInteger[i]], Length[FactorInteger[i-1]]<Length[FactorInteger[i]], Length[FactorInteger[i+1]]<Length[FactorInteger[i]], Length[FactorInteger[i+2]]<Length[FactorInteger[i]]], Print[i]]; i++ ]
gr3Q[{a_, b_, c_, d_, e_}]:=And@@Thread[c>{a, b, d, e}]; Flatten[Position[ Partition[ PrimeNu[Range[500]], 5, 1], _?(gr3Q[#]&)]]+2 (* Harvey P. Dale, Dec 17 2014 *)
CROSSREFS
Sequence in context: A327157 A336216 A309312 * A101939 A290466 A293188
KEYWORD
easy,nonn
AUTHOR
Neil Fernandez, Dec 21 2004
STATUS
approved