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impractical number (Definition)

An impractical number $n$ is an even abundant number that is not a practical number under the second definition. The first few impractical numbers are 70, 102, 114, 138, 174, 186, 222, 246, 258, 282, 318, 350, 354, 366, 372, 402, 426, 438, 444, 474, 490, 492, 498; these are listed in A007621 of Sloane's OEIS.



"impractical number" is owned by PrimeFan. [ owner history (1) ]
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See Also: practical number
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Cross-references: OEIS, practical number, abundant number, even

This is version 1 of impractical number, born on 2008-06-05.
Object id is 10665, canonical name is ImpracticalNumber.
Accessed 402 times total.

Classification:
AMS MSC: 11A25 (Number theory :: Elementary number theory :: Arithmetic functions; related numbers; inversion formulas)
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