[GuardCat]

function multiplyMembers(start, end) {
	var k, arr = [];
	function arrayMultiply (arr) {
		var result = 1, x;
		for (x = 0; x < arr.length; x++) {
			result *= +arr[x];
		}
		return result;
	}
	for (k = start; k <= end; k++) {
		arr.push(3 * (k + 1) / 7 * k + 9);
	}
	return arrayMultiply(arr)
}
alert (multiplyMembers(1, 10));