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A240845
Numbers m equal to the product of all of their integral proper roots (defined as numbers k in the range 1 < k < m such that k^j = m for some j).
0
64, 729, 15625, 46656, 117649, 1000000, 1771561, 2985984, 4826809, 7529536, 11390625, 24137569, 34012224, 47045881, 64000000, 85766121, 113379904, 148035889, 191102976, 268435456, 308915776, 481890304, 594823321, 729000000, 887503681, 1291467969, 1544804416, 1838265625
OFFSET
1,1
COMMENTS
Numbers of the form a^b where a is a number that is not a perfect power and b is a perfect number (equal to the sum of its divisors). In other words, A007916^A000396.
EXAMPLE
64 is a term because its roots are 2, 4, and 8, and 2*4*8 = 64.
CROSSREFS
Sequence in context: A074154 A351604 A343286 * A153160 A113851 A046455
KEYWORD
nonn
AUTHOR
J. Lowell, Apr 13 2014
EXTENSIONS
More terms from Jinyuan Wang, Jun 19 2021
STATUS
approved