There are 36 puzzles, which have multiple solutions. Their
numbers are 27, 39, 69, 81, 117, 123, 135, 183, 191, 195, 225, 249,
257, 267, 309, 352, 381, 423, 435, 441, 489, 495, 513, 525, 537, 609,
639, 675, 705, 765, 789, 807, 825, 831, 945 and 957.