Use the formula for finding the sum 1+2+3+...+n to discover a formula for finding the sum 8+16+24+...+8n.
The formula for the sum 8+16+24...+8n is S = ?

Question

Use the formula for finding the sum 1+2+3+...+n to discover a formula for finding the sum 8+16+24+...+8n.  
The formula for the sum 8+16+24...+8n is S = ?

anonymous · Answer

Do you mean the method of Gauss?

nincompoop · Answer

$$\sum_{i=1}^{n}i$$

nincompoop · Answer

now do it where it is 2i 
1+2+4+8+16.... +n

nincompoop · Answer

but you can't just use 2i

nincompoop · Answer

because your first term is not 2

nincompoop · Answer

yeah 8i if your first term is 8 then an increment of twice the i term

nincompoop · Answer

@Loser66 sorry,
 I was just demonstrating a pattern, not the answer. but since you already laid it out, might as well go all the way

nincompoop · Answer

nah it's cool I didn't even realize you were on it