The numbers above increase in increments as follow: 3,5,7,9…

We see that squares also increase in this pattern:

1,4,9,16,25,36,49… ==> increase  by 3,5,7,9,…

So pattern is (n-squared + 5)

since it is actually

(1+5), (4+5),(9+5),(16+5),(25+5) …