15
Chat with our AI personalities
4 6 9 13 18 24 31 39 ...... Add 2 to 4 to get 6 then add 3 to 6 to get 9 then add 4 to 9 to get 13 and so on.
we will add -3 :)
15
Add -3 to 9 because 9+(-3) = 6 Alternatively add s to the Roman numeral of ix which is 9 which then becomes six.
-3