Posted by Kenzie on .
what are the next 3 numbers after 1,+4,9,+16

Math 
Reiny,
looks like we are taking the perfect squares and alternating them  and +

Math 
Bosnian,
A perfect square is any rational number that is the square of another rational number.
1 ^ 2 = 1
2 ^ 2 = 4
5 ^ 2 = 25
6 ^ 2 = 36
7 ^ 2 = 49
etc.
Your series is a perfect square with negative odd numbers.
The next 3 numbers are :
 25 , 36 ,  49