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 A239586 #18 Oct 10 2024 15:29:52 %S A239586 2,3,3,5,7,5,7,5,7,7,11,13,13,17,19,17,19,23,17,23,29,19,31,19,29,23, %T A239586 31,37,23,41,43,37,29,47,31,23,41,29,43,53,31,47,37,59,29,61,53,41,37, %U A239586 31,43,67,59,41,71,61,47,73,43,29,37,79,67,47,31,53,83 %N A239586 Prime factor >= other prime factor of n-th brilliant number, cf. A078972. %C A239586 a(n) = A006530(A078972(n)) = A078972(n) / A239585(n). %C A239586 A055642(a(n)) = A055642(A239585(n)). %H A239586 Reinhard Zumkeller, <a href="/A239586/b239586.txt">Table of n, a(n) for n = 1..20000</a> %H A239586 Dario Alpern, <a href="https://www.alpertron.com.ar/BRILLIANT.HTM">Brilliant Numbers</a> %e A239586 See A239585. %t A239586 Table[With[{f = FactorInteger[k]}, If[Total[f[[All, 2]]] == 2 && Length[Union[IntegerLength[f[[All, 1]]]]] == 1, f[[-1, 1]], Nothing]], {k, 1000}] (* _Paolo Xausa_, Oct 02 2024 *) %t A239586 dlist2[d_] := Union[Times @@@ Tuples[Prime[Range[PrimePi[10^(d-1)] + 1, PrimePi[10^d]]], 2]]; (* Generates terms with d-digits prime factors -- faster but memory intensive *) %t A239586 Map[FactorInteger[#][[-1,1]]&,Flatten[Array[dlist2,2]]] (* _Paolo Xausa_, Oct 08 2024 *) %o A239586 (Haskell) %o A239586 a239586 n = a078972 n `div` a239585 n %Y A239586 Subsequence of A084127. %Y A239586 Cf. A006530, A055642, A078972, A239585. %K A239586 nonn,look,base %O A239586 1,1 %A A239586 _Reinhard Zumkeller_, Mar 22 2014