Question

a playground is being designed where children can interact with their friends in certain combinations
if there is one 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 3 children, there can 39 interactions.
which recursive equation represents the patterns?

can someone please help me

Answer 1

There must be a mistake below:

if there are 3 children, there can be 12 interactions.
if there 3 children, there can 39 interactions.