Question

I am trying to find the next number in this number sequence and I dont know how! its like this, 2,9,37,149,597,2389, ... whats the next number?

Answer 1

$\bf 2~~,~~\stackrel{2(4)+1}{9}~~,~~\stackrel{9(4)+1}{37}~~,~~\stackrel{37(4)+1}{149}~~,~~\stackrel{149(4)+1}{597}~~,~~\stackrel{597(4)+1}{2389}~~,~~\boxed{\stackrel{2389(4)+1}{9557}}$