Definition:Almost Perfect Number/Definition 3

Definition

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

$n$ is almost perfect if and only if it is exactly one greater than the sum of its aliquot parts.

Sequence

The sequence of almost perfect numbers begins:

$1, 2, 4, 8, 16, 32, 64, 128, \ldots$

Also see

• Equivalence of Definitions of Almost Perfect Number

Sources

• 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $12$
• 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $16$
• 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $12$
• 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $16$