Value of a random variable X at Time t

I defined a vector P that contains my probability distribution for a Dice
Roll, i.e. 6 equal probabilities for each outcome.

Now, I want to define a variable T5 such that P[T5=t] = P{Xt is the first
random variable with outcome 5}
In other words: I start my process of tossing a die and T5 is the first time
a 5 is diced.

How would I define it with an expression?



--
Sent from: https://octave.1599824.n4.nabble.com/Octave-General-f1599825.html