<s>[INST] Skip a number in a summation $$\sum_{n=1}^{10} n^2$$
Returns:

$1 + 4 + 9 + 16 + 25 + 36 + 49 + 64 + 81 + 100$

and I would like it to return:

$1 + 9 + 25 + 49 + 81 + 121 + 169 + 225 + 289 + 361$

How will I go about this and, more importantly, how does it work?
 [/INST] You are looking for $1^2 + 3^2 +5^2 +7^2 +9^2 +11^2+13^2+15^2+17^2 +19^2$ 
so whats wrong with 
$$\sum_{n=0}^9(2n+1)^2$$
or 
$$\sum_{n=1}^{10}(2n-1)^2$$
It's $2n$ because we are going up in twos
</s>