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 A108871 #7 Apr 05 2019 17:19:23 %S A108871 11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,143, %T A108871 187,202,206,209,214,218,221,226,247,253,254,262,274,278,298,299,302, %U A108871 303,309,314,319,321,323,326,327,334,339,341,346,358,362,377,381,382,386 %N A108871 Numbers n such that the number of digits required to write the prime factors of n is equal to the number of divisors of n. %C A108871 190333 has 10 divisors and 10 digits in its prime factorization. What is the next term in this sequence with more divisors and digits? %C A108871 2093663 has 12 divisors and 12 digits in its prime factorization. - _Harvey P. Dale_, Apr 05 2019 %C A108871 Prime factors are counted with multiplicity. - _Harvey P. Dale_, Apr 05 2019 %e A108871 143 is a term because it takes 4 digits to write its prime factorization %e A108871 143=11*13 and has 4 divisors [1, 11, 13, 143]. %t A108871 ndQ[n_]:=Total[#[[2]]IntegerLength[#[[1]]]&/@FactorInteger[n]] == DivisorSigma[ 0,n]; Select[Range[2,500],ndQ] %Y A108871 Cf. A076649. %K A108871 base,easy,nonn %O A108871 1,1 %A A108871 _Jason Earls_, Jul 13 2005