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)).

5, 1683, 3678726, 22377473783

Offset: 1

Author

Fred Schneider, Sep 09 2006

Keywords

• hard
• more
• nonn
• uned

Comments

These were found by R. Gerbicz.

Examples

			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.
		

Links

• Fred Schneider and R. Gerbicz, Smooth Power Trios.

Crossrefs

Cf. A122463, A122464.