(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Could anyone please help me understand this notation? What is "it" under the variables? Is it some kind of sequence notation with 2 dimensions, or sequence notation which has the sequence member number multiplied by some other variable? What is this?

Also, what could 0 over z mean, other than 0 exponent?

2. Relevant equations

3. The attempt at a solution

Tried Google search without help.

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Sequence with 2 parameters (?)

**Physics Forums | Science Articles, Homework Help, Discussion**