A363634 Lucky numbers that are products of smaller lucky numbers.

1, 9, 21, 49, 63, 75, 93, 99, 105, 111, 129, 135, 169, 189, 195, 201, 219, 231, 237, 259, 261, 273, 297, 357, 399, 429, 477, 483, 489, 495, 511, 553, 559, 579, 615, 621, 645, 651, 693, 723, 729, 735, 777, 801, 805, 819, 855, 867, 897, 903, 925, 931, 957, 961

Offset: 1

Author

Pontus von Brömssen, Jun 19 2023

Keywords

• nonn

Examples

			1 is a term because it is a lucky number and equals the empty product.
21 is a term because 21 = 3*7 and both 21 and the two factors 3 and 7 are lucky numbers.
729 is a term because 729 = 9*9*9 and both 729 and 9 are lucky numbers. (This is the first term that requires more than two factors.)
		

Crossrefs

Cf. A000959, A363635, A363636.