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Smallest of three consecutive squarefree numbers having equal numbers of prime factors.
4

%I #15 Feb 24 2021 03:52:58

%S 33,85,93,141,201,213,217,301,393,445,633,697,921,1041,1137,1261,1309,

%T 1345,1401,1641,1761,1837,1885,1893,1941,1981,2013,2101,2181,2217,

%U 2305,2361,2433,2461,2517,2641,2665,2721,2733,3097,3385,3601,3693,3729,3865

%N Smallest of three consecutive squarefree numbers having equal numbers of prime factors.

%H Amiram Eldar, <a href="/A075039/b075039.txt">Table of n, a(n) for n = 1..10000</a>

%F A001221(a(n)) = A001222(a(n)) = A001221(a(n)+1) = A001222(a(n)+1).

%e 33 is a member as 33, 34 and 35 are of the form p*q where p and q are primes.

%t Select[Range[4000], AllTrue[# + Range[0, 2], SquareFreeQ] && Equal @@ PrimeNu[# + Range[0, 2]] &] (* _Amiram Eldar_, Feb 24 2021 *)

%Y Cf. A001221, A001222, A005117, A052214, A086263, A039833.

%K nonn

%O 1,1

%A _Amarnath Murthy_, Sep 03 2002

%E More terms from _Matthew Conroy_, Sep 08 2002

%E Edited by _Reinhard Zumkeller_, Jul 14 2003

%E Offset corrected by _Amiram Eldar_, Feb 24 2021