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A036899 Products of pairs of consecutive refactorable numbers. 0
2, 72, 2311920, 2562840000, 3844062000, 10617344640, 39923436672, 49213207440, 72555078960, 215073801360, 476873804160, 719511945840, 972291644352, 1567905917760, 2012086928880, 4707721763712, 7251605387280 (list; graph; refs; listen; history; internal format)
OFFSET

0,1

COMMENTS

The product of a pair of consecutive refactorable numbers is itself refactorable.

LINKS

S. Colton, Refactorable Numbers - A Machine Invention, J. Integer Sequences, Vol. 2, 1999, #2.

S. Colton, HR - Automatic Theory Formation in Pure Mathematics

EXAMPLE

8 is refactorable because tau(8)=4 and 4 divides 8. 9 is refactorable because tau(9)=3 and 3 divides 9. So 8*9 = 72 is in the sequence.

CROSSREFS

A033950.

Sequence in context: A062082 A067689 A079478 * A041647 A083018 A062552

Adjacent sequences:  A036896 A036897 A036898 * A036900 A036901 A036902

KEYWORD

nonn

AUTHOR

Simon Colton (simonco(AT)cs.york.ac.uk)

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Last modified February 14 06:09 EST 2012. Contains 205570 sequences.