OFFSET
1,1
COMMENTS
Prime factors counted without multiplicity. - Harvey P. Dale, Dec 17 2014
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
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
KEYWORD
easy,nonn
AUTHOR
Neil Fernandez, Dec 21 2004
STATUS
approved