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A321495 Numbers k such that k and k+1 have at least 5 but not both exactly 5 distinct prime factors. 6

%I #6 Nov 13 2018 12:47:30

%S 728364,1565564,1774409,1817529,1923635,2162094,2187185,2199834,

%T 2225894,2369850,2557190,2594514,2659734,2671305,2794154,2944689,

%U 2964884,3126045,3139730,3170244,3244955,3273809,3279639,3382379,3387054,3506810,3555110,3585945,3686969,3711630

%N Numbers k such that k and k+1 have at least 5 but not both exactly 5 distinct prime factors.

%C Complement of A140079 (k and k+1 have exactly 5 distinct prime factors) in A321505 (k and k+1 have at least 5 distinct prime factors).

%F A321505 \ A140079.

%t aQ[n_]:=Module[{v={PrimeNu[n],PrimeNu[n+1]}},Min[v]>4 && v!={5,5}]; Select[Range[120000], aQ] (* _Amiram Eldar_, Nov 12 2018 *)

%o (PARI) is(n)=vecmin(n=[omega(n), omega(n+1)])>4&&n!=[5,5]

%Y Cf. A140079, A321505; A321494, A321496 (analog for 4 & 6 factors).

%K nonn

%O 1,1

%A _M. F. Hasler_, Nov 12 2018

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