

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
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OFFSET

1,1


COMMENTS

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


LINKS



FORMULA



EXAMPLE

8 and 9 are consecutive refactorable numbers, so 8*9 = 72 is in the sequence.


PROG

(PARI) isrefac(n) = ! (n % numdiv(n));
lista(nn) = {for (n=1, nn, if (isrefac(n) && isrefac(n+1), print1(n*(n+1) ", ")); ); } \\ Michel Marcus, Aug 31 2013


CROSSREFS



KEYWORD

nonn


AUTHOR

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


STATUS

approved



