A108635 Semiprimes with property that digits are in nonincreasing order.

4, 6, 9, 10, 21, 22, 33, 51, 55, 62, 65, 74, 77, 82, 85, 86, 87, 91, 93, 94, 95, 111, 221, 321, 411, 422, 511, 533, 542, 543, 551, 553, 554, 611, 622, 633, 655, 662, 721, 731, 753, 755, 763, 766, 771, 831, 841, 842, 843, 851, 862, 865, 866, 871, 886, 921, 922

Offset: 1

Author

Zak Seidov, Jun 14 2005

Keywords

• nonn
• base
• easy
• less

Examples

			The semiprime 14 is missing because 4 > 1.
		

Crossrefs

Cf. A108634.

Programs

Mathematica

Select[Range[1000], Plus@@Last/@FactorInteger[ # ]\[Equal]2&&OrderedQ[Reverse[IntegerDigits[ # ]]]&]