A097270 Numbers that are the difference of two nonzero squares but not the sum of two nonzero squares.

3, 7, 9, 11, 12, 15, 16, 19, 21, 23, 24, 27, 28, 31, 33, 35, 36, 39, 43, 44, 47, 48, 49, 51, 55, 56, 57, 59, 60, 63, 64, 67, 69, 71, 75, 76, 77, 79, 81, 83, 84, 87, 88, 91, 92, 93, 95, 96, 99, 103, 105, 107, 108, 111, 112, 115, 119, 120, 121, 123, 124, 127, 129, 131, 132