0,3,8,60,51,62,93,45,?,0,120,440,960 We notice that the first three terms are 1 less than the squares 1²,2²,3², but then we ask: what does 60 have to do with 4²=16? Then it occurs to us that if we reverse the digits of 16 and subtract 1, we get 61-1=60. So we try that scheme. When we "reverse the single digit" of a 1-digit number we get the same 1-digit number. That's why the first three numbers are the same as 1 less than the squares. Square 1, get 1 Reverse the single digit, get 1 Subtract 1, get 0. Square 2, get 4 Reverse the single digit, get 4 Subtract 1, get 3. Square 3, get 9 Reverse the single digit, get 9 Subtract 1, get 8. Square 4, get 16 Reverse the digits, get 61 Subtract 1, get 60. Square 5, get 25 Reverse the digits, get 52 Subtract 1, get 51. Square 6, get 36 Reverse the digits, get 63 Subtract 1, get 62. Square 7, get 49 Reverse the digits, get 94 Subtract 1, get 93. Square 8, get 64 Reverse the digits, get 46 Subtract 1, get 45. Square 9, get 81 Reverse the digits, get 18 Subtract 1, get 17. <--- that the answer. But let's keep going as a check. Square 10, get 100 Reverse the digits, get 001, or just 1 Subtract 1 get 0 Square 11, get 121 Reverse the digits, get 121 Subtract 1 get 120 Square 12, get 144 Reverse the digits, get 441 Subtract 1 get 440 Square 13, get 169 Reverse the digits, get 961 Subtract 1 get 960 Edwin