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 A087321 #12 Feb 23 2021 05:21:50 %S A087321 1,4,9,4,25,36,49,8,9,100,121,36,169,196,225,16,289,36,361,100,441, %T A087321 484,529,216,25,676,27,196,841,900,961,32,1089,1156,1225,36,1369,1444, %U A087321 1521,1000,1681,1764,1849,484,225,2116,2209,1296,49,100,2601,676,2809,216 %N A087321 Smallest multiple of n which is a perfect power (at least a square) of a squarefree number. %H A087321 Amiram Eldar, <a href="/A087321/b087321.txt">Table of n, a(n) for n = 1..10000</a> %F A087321 If n = p^a*q^b*r^c... p, q, r are primes and max(a, b, c, ...) = K then a(n) = p^K*q^K*r^K... %F A087321 a(n) = A007947(n)^max(A051903(n), 2). - _David Wasserman_, May 04 2005 %e A087321 a(12) = 3*12 = 36 = 6^2. %e A087321 a(24) = 9*24 = 216 = 6^3. %t A087321 a[n_] := (Times @@ First@#)^(Max[Max @@ Last@#, 2]) &@ Transpose @ FactorInteger[n]; Array[a, 100] (* _Amiram Eldar_, Feb 23 2021 *) %Y A087321 Cf. A007947, A051903, A072774, A087320. %K A087321 easy,nonn %O A087321 1,2 %A A087321 _Amarnath Murthy_, Sep 03 2003 %E A087321 More terms from _David Wasserman_, May 04 2005