A075039 Smallest of three consecutive squarefree numbers having equal numbers of prime factors.

33, 85, 93, 141, 201, 213, 217, 301, 393, 445, 633, 697, 921, 1041, 1137, 1261, 1309, 1345, 1401, 1641, 1761, 1837, 1885, 1893, 1941, 1981, 2013, 2101, 2181, 2217, 2305, 2361, 2433, 2461, 2517, 2641, 2665, 2721, 2733, 3097, 3385, 3601, 3693, 3729, 3865

Offset: 1

Author

Amarnath Murthy, Sep 03 2002

Keywords

• nonn

Examples

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

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

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

Programs

Mathematica

Select[Range[4000], AllTrue[# + Range[0, 2], SquareFreeQ] && Equal @@ PrimeNu[# + Range[0, 2]] &] (* Amiram Eldar, Feb 24 2021 *)

Formula

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

Extensions

More terms from Matthew Conroy, Sep 08 2002

Edited by Reinhard Zumkeller, Jul 14 2003

Offset corrected by Amiram Eldar, Feb 24 2021