The First Solutions
Chessboard size 55×55
1, 3, 5, 2, 4, 9, 11, 13, 15, 6, 8, 19, 7, 22, 10, 25, 27, 29, 31, 12, 41, 43, 46, 50, 47, 45, 54, 42, 53, 55, 44, 48, 51, 49, 52, 23, 14, 28, 17, 33, 20, 16, 34, 24, 18, 21, 32, 30, 37, 26, 40, 36, 39, 35, 38