i'll give a medal and become a fan if someone can help me with this question ..How can you represent the terms of a sequence explicitly? How can you represent them recursively?

Question

anonymous · Answer

1/Explicitly: with a formula that contains and uses n, the term number. 
 Example. The sequence 9, 12, 15, 18.......... can be represented by the formula an = 3n + 6. 
 2/Recursively: with a formula containing and using a(n-1), the previous term. 
 Example: 9, 12, 15, 18...........can be represented by the formula an = a(n-1)+3. The first term (a1) needs to be specified (a1 = 9).

anonymous · Answer

that helped alot thank you @david3395

anonymous · Answer

but i know you copied that from somewhere , just don't know where

anonymous · Answer

yea im not that smart just goin around trying to help