I think:
if n = 1 => 14
if n = 2 => 16 (+1040, 2080)
if n > 2 => 17 (+10...080...0)
Is not it???

Sorry for my worse English.

For example, 1144 and 2288 are interesting too.

n = 1
n = 2
n = 3
n = 4
.....
.....
.....
n = 16


i think this tests will be useful for u