SOLUTION: I need an explicit formula for the sequence : {2, 6, 12, 20} I have noticed that the pattern is +4, +6, +8 and so on, but I can't figure out how to write the formula.

Algebra ->  Sequences-and-series -> SOLUTION: I need an explicit formula for the sequence : {2, 6, 12, 20} I have noticed that the pattern is +4, +6, +8 and so on, but I can't figure out how to write the formula.      Log On


   

Question 586731: I need an explicit formula for the sequence : {2, 6, 12, 20} I have noticed that the pattern is +4, +6, +8 and so on, but I can't figure out how to write the formula.
Answer by ad_alta(240) About Me  (Show Source):
You can put this solution on YOUR website!
Use A(n)=n(n+1) [since 1(1+1)=2, 2(2+1)=6)...4(4+1)=20]