Question

A playground is being designed where children can interact with their friends in certain combinations.

If there is 1 child, there can be 0 interactions.
If there are 2 children, there can be 3 interactions.
If there are 3 children, there can be 12 interactions.
If there are 4 children, there can be 39 interactions.

Which recursive equation represents the pattern?

Answer 1

please help me

Answer 2

how would i write the recursive equation

Answer 3

Make a table:

Now, using ( ) + - / x try to turn the n into the related i.

Hint: there's an n-1 and a ^2