for maths coursework how would you justify a 3d cross that keeps building up?(borders coursework)?

Question

I need help with the justification- te total for the cross shpe in layers goes 1, 5, 13, 25, 41, 61

Answer 1

Your question is unclear.
However, there is a pattern with the numbers that might be of help to you.
where:
n1 - is first number.
n2 - is second number.
n3 - is third number.
n4 - is forth number
and so on.

n1 + 1(4), n2 + 2(4), n3 +3(4), n4 + 4(4), .....etc.

Answer 2

I don't know what you mean by "justify" in this context. Also it is not obvious, at least to me, how you are building up the cross to get these numbers. I think that you will need to make things clearer before I can help you.