Answer :
For every other number, you multiply by 2 and then add 3.
2 x 2 is 4, then 4 + 3 is 7, then 7 x 2 is 14, then 14 + 3 is 17...
2 x 2 is 4, then 4 + 3 is 7, then 7 x 2 is 14, then 14 + 3 is 17...