A046442 Semiprimes whose two prime factors are distinct in length.

22, 26, 33, 34, 38, 39, 46, 51, 55, 57, 58, 62, 65, 69, 74, 77, 82, 85, 86, 87, 91, 93, 94, 95, 106, 111, 115, 118, 119, 122, 123, 129, 133, 134, 141, 142, 145, 146, 155, 158, 159, 161, 166, 177, 178, 183, 185, 194, 201, 202, 203, 205, 206, 213, 214, 215, 217

Offset: 1

Author

Patrick De Geest, Jul 15 1998

Keywords

• nonn
• base

Comments

Semiprimes (A001358) that are not brilliant numbers (A078972). - Bernard Schott, Jul 29 2022

Examples

			203 because 203 = 7 * 29, which have 1 and 2 digits, respectively.
		

Crossrefs

Equals A001358 \ A078972.

Programs

Mathematica

Take[Union[Times@@@Select[Subsets[Prime[Range[50]],{2}],IntegerLength[#[[1]]]!=IntegerLength[#[[2]]]&]],60] (* Harvey P. Dale, Dec 29 2010 *)