Definition:Deficient Number/Definition 3

Definition

Let $n \in \Z_{\ge 0}$ be a positive integer.

$n$ is deficient if and only if it is greater than its aliquot sum.

Sequence

The sequence of deficient numbers begins:

$2, 3, 4, 5, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 19, 21, \ldots$

Also see

• Equivalence of Definitions of Deficient Number

Sources

• 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $12$
• 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $12$
• 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): deficient number