To run: "node collatz.js <integer>". Collatz Conjecture in Javascript. Left column is the number of steps to get to 1.

collatz.js

// Warning: maximum value for a variable of type Number (no bitwise or shift operators allowed): 9,007,199,254,740,991
let x = parseInt(process.argv[2]);
if(isNaN(x)) process.exit(1);
else{
  if(x < 1){
    process.exit(1);
  }
  else{
   let n = 0; console.log(`${n} ${x}`);
    while (x !== 1){
     if(x%2 === 0){
       x = x/2; n++; console.log(`${n} ${x}`);
     }
     else{
       x = (3*x)+1; n++; console.log(`${n} ${x}`);
     }
    } 
  }  
}