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A101939 Numbers n with omega(n) > omega of 3 nearest larger and 3 nearest smaller neighbors. 1
6, 30, 42, 60, 66, 70, 78, 84, 90, 110, 114, 120, 126, 150, 174, 186, 190, 204, 210, 246, 290, 294, 300, 322, 330, 336, 385, 390, 414, 420, 450, 462, 510, 540, 546, 570, 630, 660, 690, 714, 720, 770, 780, 786, 798, 840, 846, 858, 870, 910 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..10000

EXAMPLE

6 is in the sequence because it has two unique prime factors (2 and 3) whereas 3, 4, 5, 7, 8 and 9 each have fewer.

MATHEMATICA

For[i=3, i<1000, If[And[Length[FactorInteger[i-3]] < Length[FactorInteger[i]], 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]], Length[FactorInteger[i+3]] < Length[FactorInteger[i]]], Print[i]]; i++]

Clear[noQ]; noQ[n_]:=And@@(#<Max[n]&/@Drop[n, {4}]); Off[Drop::normal]; Off[ Drop::seqs]; Flatten[Position[Partition[ PrimeNu[Range[1000]], 7, 1], _?noQ]]+ 3 (* Harvey P. Dale, Mar 05 2012 *)

Select[Range[650], PrimeNu[#] > Max[PrimeNu[# - 1], PrimeNu[# - 2], PrimeNu[# - 3], PrimeNu[# + 1], PrimeNu[# + 2], PrimeNu[# + 3]] &] (* G. C. Greubel, May 21 2017 *)

CROSSREFS

Cf. A001221, A076763, A101937.

Sequence in context: A327157 A309312 A101937 * A290466 A293188 A080289

Adjacent sequences:  A101936 A101937 A101938 * A101940 A101941 A101942

KEYWORD

easy,nonn

AUTHOR

Neil Fernandez, Dec 21 2004

STATUS

approved

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Last modified January 28 06:29 EST 2020. Contains 331317 sequences. (Running on oeis4.)