A046444 Composite numbers whose 4 prime factors are distinct in length.

2241998, 2250886, 2264218, 2268662, 2286394, 2290882, 2295326, 2295458, 2308658, 2309054, 2313586, 2330878, 2335322, 2336246, 2340778, 2354374, 2357542, 2361986, 2375186, 2375318, 2377034, 2381566, 2384602, 2398726

Offset: 1

Author

Patrick De Geest, Jul 15 1998

Keywords

• nonn
• base

Comments

Equivalently, the products of 4 prime numbers that have distinct lengths when written in decimal. - Peter Munn, May 30 2023

Examples

			2241998 because 2241998 = 2 * 11 * 101 * 1009, which have 1, 2, 3, and 4 digits, respectively.
		

Crossrefs

Subsequence of A046386.

Programs

Mathematica

Select[Range[24*10^5],PrimeNu[#]==4&&Length[Union[IntegerLength/@ FactorInteger[ #][[All,1]]]]==4&] (* Harvey P. Dale, Jan 12 2020 *)