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A122465 Smooth Power Quartets: The m-th number in the sequence, n, is part of the minimum quartet of numbers n through n-3 such that the highest prime factor of each number x <= floor(x^(1/m)). 2

%I

%S 5,1683,3678726,22377473783

%N Smooth Power Quartets: The m-th number in the sequence, n, is part of the minimum quartet of numbers n through n-3 such that the highest prime factor of each number x <= floor(x^(1/m)).

%C These were found by R. Gerbicz.

%H Fred Schneider and R. Gerbicz, <a href="http://www.mersenneforum.org/showthread.php?t=5647">Smooth Power Trios</a>.

%e 1680 = 2^4*3*5*7, 1681 = 41^2, 1682 = 2*29^2, 1683 = 3^2*11*17; 7 < floor(sqrt(1680)) = 40 and 41 <= floor(sqrt(1681)) = 41, so 1683 is a term.

%Y Cf. A122463, A122464.

%K hard,more,nonn,uned

%O 1,1

%A _Fred Schneider_, Sep 09 2006

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Last modified November 27 10:50 EST 2022. Contains 358381 sequences. (Running on oeis4.)