SOLUTION: Hi, Could you help me find the 7th, 8th, and 9th terms of the following sequence (1, 2, 3, 6, 11, 20, ...)? As the sequence progresses, each number equals the sum of the pre

Algebra ->  Sequences-and-series -> SOLUTION: Hi, Could you help me find the 7th, 8th, and 9th terms of the following sequence (1, 2, 3, 6, 11, 20, ...)? As the sequence progresses, each number equals the sum of the pre      Log On


   

Question 524497: Hi,
Could you help me find the 7th, 8th, and 9th terms of the following sequence
(1, 2, 3, 6, 11, 20, ...)? As the sequence progresses, each number equals the sum of the previous three numbers (ie 20 = 11 + 6 +3), but I can't figure out how they got 1 and 2. Another idea is that every even term equals the previous term plus 3 to increasing powers (3 to the zero is 1, 3 to the first is 3, etc-- sorry no exponents or superscript in the text box!)and every odd term is simply a summation. I'd really appreciate any help you can give.
Thanks very much,
Amy
Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
Each number after the third number equals the sum of the previous three numbers. The first three are completely arbitrary. Use these facts to find the 7th, 8th and 9th terms.