// Created by Nikolay Nachev var hardyNumberChecker = ( function (){ var checker = {}; Object.defineProperty( checker, 'init', { value: function() { this._cubes = []; return this; } }); //memoize the cubes of numbers Object.defineProperty( checker, 'cubes', { value : function(number) { if (this._cubes[number] === undefined) { this._cubes[number] = number * number * number; } return this._cubes[number]; } }); Object.defineProperty( checker, 'check', { enumerable: true, value: function(number) { //init solution var solution = { isHardyRamanujanNumber: false, solutions: [] }; //simple input validation if ( isNaN(number) || (( number | 0 ) <= 1 ) ) return solution; var secNumberInt, secNumberCube; var numbersPassed = []; //establish loop limit var maxNumber = Math.ceil( Math.pow( number, 1/3 ) ); for (var i = 1; i <= maxNumber; i++) { secNumberInt = Math.ceil( Math.pow( number - this.cubes(i), 1/3) ); secNumberCube = this.cubes(secNumberInt); //exlude a^3 + 0^3 = c if ( secNumberInt !== 0 ) { if (secNumberCube + this.cubes(i) == number) { // exclude a^3 + b^3 = b^3 + a^3 if (numbersPassed.indexOf(secNumberInt) == -1) { //add the counter to the exclude list numbersPassed.push(i); //add the solution solution.solutions.unshift({ firstNumber: i, secondNumber: secNumberInt }); } } } } if (solution.solutions.length > 0 ) { solution.isHardyRamanujanNumber = true; } return solution; } }) return checker; }()); var checker = hardyNumberChecker.init(); function check() { number = document.getElementById('numberBox').value; var solution = checker.check(number); var div = document.getElementById('solutionContainer'); div.style.display = "block"; div.innerHTML = ''; if (!solution.isHardyRamanujanNumber) { div.innerHTML = '' + number + ' is not a Hardy-Ramanujan number.'; } else { div.innerHTML = '' + number + ' is a Hardy-Ramanujan number.

Possible solutions:
'; solution.solutions.forEach( function(sol) { div.innerHTML += '' + sol.firstNumber + '³ + ' + sol.secondNumber + '³
'; } ); } }

Hardy-Ramanujam Number