Finding next number in a series

[Iriemon]

I have a series of numbers in one column (sample):

1
2
4
5
7
16


What formula would find the smallest available number? In other words how
would I find "3"?

 

[Bernd P]

Hello,

Array-enter
=INDEX(ROW(INDIRECT(MIN(A1:A6)&":"&MAX(A1:A6))),MATCH(TRUE,ISNA(MATCH(ROW(INDIRECT(MIN(A1:A6)&":"&MAX(A1:A6))),A1:A6,0)),
0))

Regards,
Bernd

 

[T. Valko]

Assuming the range of numbers is 1 to 16.

Array entered** :

=SMALL(IF(ISNA(MATCH(ROW(INDIRECT("1:16")),A2:A7,0)),ROW(INDIRECT("1:16"))),1)

** array formulas need to be entered using the key combination of
CTRL,SHIFT,ENTER (not just ENTER). Hold down both the CTRL key and the SHIFT
key then hit ENTER.