Aft on IntegerPartition

The size minus the larger of the largest part and the number of parts.

On IntegerPartition

Called as CombinatorialStat(x, "Aft"). The head's page has its examples.

Live

FindStat St001214

The aft of an integer partition.

Object	Value
`[]`	`0`
`[1]`	`0`
`[2]`	`0`
`[3]`	`0`
`[4]`	`0`
`[5]`	`0`
`[6]`	`0`
`[7]`	`0`

Data from FindStat, the combinatorial statistic finder; the page at findstat.org/St001214 has the rest.