This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A046444 #21 May 30 2023 07:43:48 %S A046444 2241998,2250886,2264218,2268662,2286394,2290882,2295326,2295458, %T A046444 2308658,2309054,2313586,2330878,2335322,2336246,2340778,2354374, %U A046444 2357542,2361986,2375186,2375318,2377034,2381566,2384602,2398726 %N A046444 Composite numbers whose 4 prime factors are distinct in length. %C A046444 Equivalently, the products of 4 prime numbers that have distinct lengths when written in decimal. - _Peter Munn_, May 30 2023 %e A046444 2241998 because 2241998 = 2 * 11 * 101 * 1009, which have 1, 2, 3, and 4 digits, respectively. %t A046444 Select[Range[24*10^5],PrimeNu[#]==4&&Length[Union[IntegerLength/@ FactorInteger[ #][[All,1]]]]==4&] (* _Harvey P. Dale_, Jan 12 2020 *) %Y A046444 Subsequence of A046386. %K A046444 nonn,base %O A046444 1,1 %A A046444 _Patrick De Geest_, Jul 15 1998