How to get the closed form of this recurrence?

[zeion]

Homework Statement

Hello,

This expression was derived from a polygon word problem and I need to find a closed form for it with repeated substitution (I think).

T(k, n) = T(k, n-1) + (k-2)(n-1) + 1

Homework Equations

The Attempt at a Solution

Get a pattern like:

= T(k, n-2) + (k - 2)(2n - 3) - 2 subs.
= T(k, n-3) + (k - 2)(3n - 6) - 3 subs.
= T(k, n-4) + (k - 2)(4n - 10) -4 subs.
.
.
.

I'm not sure how to express the 1, 3, 6, 10 sequence in terms of number of substitutions.

 

[Max.Planck]

What is the boundary coundition?
This is what I got so far.
Assuming T(k, 0) = c

T(k,n) = n+c+(k-2)*1*2*...(n-1)

 

[zeion]

Sorry I wrote the expression wrong; but I got the answer I think, thanks.