Not sure if it helps but,
Solving for k
k= 3j/j-3 , Notice J can't be equal to 3
If J and K are positive integers,
Is there a restricted domain?
Also J can't be equal to=(1,2,3,5,7,8,9,10,11,13,14,15,16,17,18,19,20,21,22, etc..) The pattern contuines so, k can be equal to 4, 6 ,12only out of the first 20 numbers.. I don't think the equation works for more... Idk.
so the sum of possible values of k is 4+6+12=22