# 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:

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