# impractical number

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.

Title impractical number ImpracticalNumber 2013-03-22 18:07:06 2013-03-22 18:07:06 PrimeFan (13766) PrimeFan (13766) 4 PrimeFan (13766) Definition msc 11A25 PracticalNumber2