

A075039


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


3



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
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OFFSET

1,1


LINKS

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


FORMULA

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


EXAMPLE

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


MATHEMATICA

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


CROSSREFS

Cf. A001221, A001222, A005117, A052214, A086263, A039833.
Sequence in context: A005238 A052214 A063838 * A039833 A250732 A080700
Adjacent sequences: A075036 A075037 A075038 * A075040 A075041 A075042


KEYWORD

nonn


AUTHOR

Amarnath Murthy, Sep 03 2002


EXTENSIONS

More terms from Matthew Conroy, Sep 08 2002
Edited by Reinhard Zumkeller, Jul 14 2003
Offset corrected by Amiram Eldar, Feb 24 2021


STATUS

approved



