(function() {
  var Hofstadter;

  function g(n) {
    var A = [],
        i;

    A[0] = 0;
    A[1] = 1;

    for (i = 2; i <= n; i++) {
      A[i] = i - A[A[i - 1]];
    }

    return A[n];
  }

  Hofstadter = {};
  Hofstadter.function = {};
  Hofstadter.function.G = g;

  d3.Hofstadter = Hofstadter;
})();