How to perform a set of commands specific amout of time?

Question

I have 3 lines of code that does the Collatz Conjecture in mathematica. the code is the following:

ClearAll[collatz];
collatz[1] = 1;
collatz[n_ /; EvenQ[n]] := (Sow[n]; collatz[n/2])
collatz[n_ /; OddQ[n]] := (Sow[n]; collatz[3 n + 1])
runcoll[n_] := Reap[collatz[n]]

this code performs until 1 is reached but I want to have the code done a specificities cnumber of times, say 10. how can I write a loop that perform this only a specific number of times?

and this has not happed btw:

 ClearAll[collatz];
    collatz[1] = 1;
n=1; While [n<11,
    collatz[n_ /; EvenQ[n]] := (Sow[n]; collatz[n/2])
    collatz[n_ /; OddQ[n]] := (Sow[n]; collatz[3 n + 1])
    runcoll[n_] := Reap[collatz[n]]
; n++]

Answer 1

You can use a counter like this:

ClearAll[collatz];
collatz[1] = 1;
collatz[n_ /; EvenQ[n], i_ /; i < 10] := (Sow[n]; collatz[n/2, i + 1])
collatz[n_ /; OddQ[n], i_ /; i < 10] := (Sow[n]; collatz[3 n + 1, i + 1])
collatz[n_, i_ /; i >= 10] := n
runcoll[n_] := Reap[collatz[n, 0]]

runcoll[100]

{22, {{100, 50, 25, 76, 38, 19, 58, 29, 88, 44}}}

The recursive functions only apply while $i < 10$ because of the condition specified with the /; syntax. When $i$ is larger than that and $n$ is not $1$, then the only definition that applies is a definition that returns $n$, thus ending the recursive chain.