SOLUTION: What is the algebraic equation for the sequence: 1,12,123,1234,12345...?

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Question 408290: What is the algebraic equation for the sequence: 1,12,123,1234,12345...?
Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
We could define a recursive sequence:

a%5Bn%5D+=+10a%5Bn-1%5D+%2B+n where a%5B1%5D+=+1.

Basically what this means is, take the n-1'th term, multiply it by 10, and then add n.