Binary Crossword Challenge This puzzle consists completely of binary numbers, so all the characters needed to fill in the squares will be 0 s or 15 . The crossword is a 44 square grid, so all numbers will be written in binary, with 4 digits; e.g., 1 will be 0001,2 will be 0010 , and 4,0100 . The NOT operation changes all 0 s to 1's and all 15 to 0 s; e.g., NOT(0110) is 1001 and NOT (1010) is 0101. Rows (Across): Columns (Down): 1. "2 Down" 2 1. NOT " 2 Across" 2. A triangular number * 2. NOT "1 Across" 3. The cube of ("4 Down" - 2) 3. "2 Across" 2 4. "3 Across" + "3 Down" 4. "4 Across" - "1 Across" * HINT: A triangular number is the number of dots in an equilateral triangle uniformly filed with dots. For example, three dots can be arranged in a triangle; thus three is a triangle number