text: export default () => `Problem 162 solution is: ${f(16n).toString(16).toUpperCase()}`;
  
  function g(n, r) {
  	if (r === 0n) return 16n ** n;
  	if (n === r) return factorial(r);
  	return (16n - r) * g(n - 1n, r) + r * g(n - 1n, r - 1n);
  }
  
  function f(n) {
  	if (n === 3n) return 4n;
  	return f(n - 1n) + 13n * g(n - 1n, 3n) + 2n * g(n - 1n, 2n);
  }
  
  function factorial(n) {
  	if (n === 0n || n === 1n) return 1n;
  	return n * factorial(n - 1n);
  }
  