- #1

- 6

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## Main Question or Discussion Point

I know n(n+1)/2 solves from 1.... n by 1's

Is there a formula where you can add up by 3's?

Example: 3 + 6 + 9 + 12 ... n

Is there a formula where you can add up by 3's?

Example: 3 + 6 + 9 + 12 ... n