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 A086297 #8 Sep 06 2020 03:46:48 %S A086297 1,2,3,2,5,6,7,2,3,10,6,14,15,2,6,10,21,6,5,3,14,30,2,35,6,10,42,15,6, %T A086297 7,10,6,14,30,21,2,70,6,15,10,3,42,30,6,14,10,105,6,14,30,5,42,2,15, %U A086297 70,6,21,30,10,6,42,35,30,21,6,14,10,210,6,14,15,30,3,35,10,42,2 %N A086297 Squarefree kernels of 7-smooth numbers. %C A086297 a(n) = A007947(A002473(n)); %C A086297 a(n) <= 210 = 7*5*3*2; range = A018336. %H A086297 Amiram Eldar, <a href="/A086297/b086297.txt">Table of n, a(n) for n = 1..10000</a> %t A086297 f[n_] := If[Max[(p = FactorInteger[n][[;; , 1]])] <= 7, Times @@ p, 0]; Select[f /@ Range[300], # > 0 &] (* _Amiram Eldar_, Sep 06 2020 *) %Y A086297 Cf. A002473, A007947, A018336. %K A086297 nonn %O A086297 1,2 %A A086297 _Reinhard Zumkeller_, Jul 15 2003