Factorial Calculator

//////////////////////////////////////////////////////////////////////////
// Written by M.Quartz of Second Life. Mon Oct 8, 2018: This script
// calculates the factorial sum of a chosen integer using a recursion
// method instead of a loop.
//
// https://en.wikipedia.org/wiki/Triangular_number
//
//////////////////////////////////////////////////////////////////////////
// Recursive functions hog memory and can heap collide very quickly
// especially with lsl scripts capped at 64k. So limit the input to
// avoid memory problems.
#define LIMIT       1600

//////////////////////////////////////////////////////////////////////////
#define int         integer
#define str         string
#define rtn         return

#define print(a)    llSay(0, a)

//////////////////////////////////////////////////////////////////////////
#define RCT         "[Recursion Test] "
#define MES1        "Enter a number to calculate it's factorial sum: \n"
#define MES2(a,b)   "Triangular sum of "+a+" = "+b+"\n"
#define ERR(a)      "Triangular sum of "+a+" = E\n"

//////////////////////////////////////////////////////////////////////////
// Recursive Function: To simulate
// this 𝚺 Formula: \sum_{x=1}^{n}x!
int x(int n)
{
    if (n <= 1)
        rtn 1;
    else
        rtn n+x(n-1); // Calls on itself
}
//////////////////////////////////////////////////////////////////////////
// Begin Events:
default
{
    state_entry()
    {
        llListen(0, "", llGetOwner(), "");
        print(RCT+MES1);
    }
    listen(int c, str N, key i, str m)
    {
        int n = (int)m;

        if (n > 0 &&
            n < LIMIT) {

            str t = (str)x(n);
            print(RCT+MES2(m,t));
        }
        else
            print(RCT+ERR(m)); // Because: 32 bit
    }
}