extravagant number

An extravagant number or wasteful number $n$ is an integer with a base $b$ representation of $k$ digits for which the prime factorization uses more than $k$ digits (with repeated prime factors grouped with exponents and the digits of those exponents counted whenever greater than 1). The first few extravagant numbers in base 10 are 4, 6, 8, 9, 12, 18, 20, 22, 24, 26, 28, 30, 33, 34, 36, 38, 39, 40, 42, 44, 45, 46, 48, etc. (listed in A046760 of Sloane’s OEIS).

References

1 D. Darling, “Economical number” in The Universal Book of Mathematics: From Abracadabra To Zeno’s paradoxes. Hoboken, New Jersey: Wiley (2004)

单词	ExtravagantNumber
释义	extravagant number An extravagant number or wasteful number $n$ is an integer with a base $b$ representation of $k$ digits for which the prime factorization uses more than $k$ digits (with repeated prime factors grouped with exponents and the digits of those exponents counted whenever greater than 1). The first few extravagant numbers in base 10 are 4, 6, 8, 9, 12, 18, 20, 22, 24, 26, 28, 30, 33, 34, 36, 38, 39, 40, 42, 44, 45, 46, 48, etc. (listed in A046760 of Sloane’s OEIS). References 1 D. Darling, “Economical number” in The Universal Book of Mathematics: From Abracadabra To Zeno’s paradoxes. Hoboken, New Jersey: Wiley (2004)
随便看	Aristotelian logic Aristotle Aristotle Arithmetic arithmetic ArithmeticalHierarchy arithmetical hierarchy ArithmeticalHierarchyIsAProperHierarchy arithmetical hierarchy is a proper hierarchy ArithmeticalRing arithmetical ring ArithmeticDerivative arithmetic derivative ArithmeticEncoding arithmetic encoding ArithmeticFunction arithmetic function ArithmeticFunctionsFormARing arithmetic functions form a ring ArithmeticgeometricharmonicMeansInequality arithmetic-geometric-harmonic means inequality ArithmeticgeometricMean arithmetic-geometric mean ArithmeticgeometricMeanAsAProduct arithmetic-geometric mean as a product