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 A303710 #14 May 04 2018 08:31:38 %S A303710 1,1,1,2,1,2,1,3,1,2,2,1,3,1,3,2,2,1,4,2,3,1,5,1,2,2,2,1,2,2,4,1,5,1, %T A303710 3,3,2,1,5,3,2,3,1,4,2,4,2,2,1,9,1,2,3,2,5,1,3,2,5,1,8,1,2,3,3,2,5,1, %U A303710 5,2,1,9,2,2,2,4,1,9,2,3,2,2,2,6,1,3,3 %N A303710 Number of factorizations of numbers that are not perfect powers using only numbers that are not perfect powers. %C A303710 Note that a factorization of a number that is not a perfect power (A007916) is always itself aperiodic, meaning the multiplicities of its factors are relatively prime. %e A303710 The a(19) = 4 factorizations of 24 are (2*2*2*3), (2*2*6), (2*12), (24). %e A303710 The a(23) = 5 factorizations of 30 are (2*3*5), (2*15), (3*10), (5*6), (30). %t A303710 radQ[n_] := And[n > 1, GCD@@FactorInteger[n][[All, 2]] === 1]; facsr[n_] := If[n <= 1, {{}}, Join@@Table[Map[Prepend[#, d] &, Select[facsr[n/d], Min@@# >= d &]], {d, Select[Divisors[n], radQ]}]]; Table[Length[facsr[n]], {n, Select[Range[100], radQ]}] %Y A303710 Cf. A001055, A001597, A007716, A007916, A052409, A052410, A281116, A303365, A303386, A303707, A303708, A303709. %K A303710 nonn %O A303710 1,4 %A A303710 _Gus Wiseman_, Apr 29 2018