A118556 Lucky numbers for which the product of the digits is also a lucky number.

1, 3, 7, 9, 13, 31, 33, 37, 73, 79, 111, 133, 135, 171, 331, 357, 535, 537, 553, 717, 735, 739, 937, 1117, 1155, 1179, 1197, 1357, 1395, 1711, 1731, 1771, 3111, 3171, 3175, 3571, 3915, 3951, 3999, 5137, 5139, 5151, 5371, 5377, 5713, 5737, 5913, 5997, 7111