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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
5, 1683, 3678726, 22377473783 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

These were found by R. Gerbicz

LINKS

Fred Schneider and R. Gerbicz, Smooth Power Trios.

EXAMPLE

Example: The 2nd term:

1680=2^4*3*5*7, 1681=41^2, 1682=2*29^2, 1683=3^2*11*17,

This satisfies because 7 < floor(1680^(1/2) = 40 and 41 <= floor(1681^(1/2))=41

PROG

Program in C written by R. Gerbicz

CROSSREFS

Cf. A122463, A122464.

Sequence in context: A123658 A057199 A198246 * A203683 A003733 A201300

Adjacent sequences:  A122462 A122463 A122464 * A122466 A122467 A122468

KEYWORD

hard,more,nonn,uned

AUTHOR

Fred Schneider (frederick.william.schneider(AT)gmail.com), Sep 09 2006

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Last modified February 17 06:27 EST 2012. Contains 205998 sequences.