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A122464 Smooth Power Trios: a(n) is the largest of three successive numbers a(n)-j, j=0..2, such that the largest prime factor of a(n)-j is <= the n-th root of a(n)-j. 2
4, 50, 134850, 116026275, 138982583000, 1348770149848002 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The fifth term was found by R. Gerbicz, the others were found by F. Schneider.

LINKS

Table of n, a(n) for n=1..6.

Fred Schneider and R. Gerbicz, Smooth Power Trios.

EXAMPLE

Example for n=6:

1348770149848002 = 2 x 3 x 7 x 23 x 41 x 61^2 x 149 x 239 x 257,

1348770149848001 = 19^3 x 89 x 103 x 229 x 283 x 331,

1348770149848000 = 2^6 x 5^3 x 11 x 29 x 109 x 151 x 163 x 197,

This satisfies because 331 <= floor(1348770149848000^(1/6)) = 332.

CROSSREFS

Cf. A122463, A122465.

Sequence in context: A193157 A235604 A221477 * A226375 A048995 A215639

Adjacent sequences:  A122461 A122462 A122463 * A122465 A122466 A122467

KEYWORD

hard,more,nonn

AUTHOR

Fred Schneider, Sep 09 2006

STATUS

approved

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Last modified December 6 12:54 EST 2016. Contains 278781 sequences.