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%I #15 Apr 18 2018 09:48:14
%S 3,4,8,21,34,35,39,45,51,55,56,57,75,76,86,87,92,93,94,95,99,116,117,
%T 118,123,134,135,142,143,144,145,146,147,159,160,161,176,177,184,188,
%U 201,202,206,207,208,213,214,215,216,217,218,225
%N Numbers n with omega(n) equal to omega(n-1) and omega (n+1).
%H G. C. Greubel, <a href="/A101932/b101932.txt">Table of n, a(n) for n = 1..5000</a>
%e 45 is in the sequence because it has 2 prime factors (3 and 5) as do 44 (2 and 11) and 46 (2 and 23).
%t For[i=1, i<1000, If[And[Length[FactorInteger[i-1]]==Length[FactorInteger[i]], Length[FactorInteger[i+1]]==Length[FactorInteger[i]]], Print[i]];i++ ]
%t Select[Range[2, 225], PrimeNu[#] == PrimeNu[# - 1] == PrimeNu[# + 1] &] (* _Jayanta Basu_, Aug 11 2013 *)
%t SequencePosition[PrimeNu[Range[300]],{x_,x_,x_}][[All,1]]+1 (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Apr 18 2018 *)
%o (PARI) isok(n) = (omega(n) == omega(n-1)) && (omega(n)==omega(n+1)) \\ _Michel Marcus_, May 05 2017
%Y Cf. A001221.
%Y Subsequence of A006049.
%K easy,nonn
%O 1,1
%A _Neil Fernandez_, Dec 21 2004
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