Is this sequence arithmetic? 1, 3, 9, 27, 81... How will I know if a sequence is arithmetic or not?

Question

parthkohli · Answer

Is $\rm 2nd ~term - 1st~ term$ equal to $\rm 3rd~term - 2nd~term$? If yes, then it's arithmetic.

anonymous · Answer

it is not arithmetic sequence 
A  sequence is arithmetic if the difference between its any two consecutive terms is same. in your question it could be arithmetic if 3-1=9-3=27-9=81-27 but as they are not equal so it is not arithmetic

aravindg · Answer

infact this is a "Geometric Progression " with common ratio 3

anonymous · Answer

Ok. Thanks guys! :)