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 A076292 #13 Jan 01 2022 09:56:28 %S A076292 1,4,8,9,16,25,27,32,36,49,64,81,100,121,125,128,169,196,216,225,243, %T A076292 256,289,343,361,441,484,512,529,625,676,729,841,900,961,1000,1024, %U A076292 1089,1156,1225,1296,1331,1369,1444,1521,1681,1764,1849,2048,2116,2187 %N A076292 Perfect powers with squarefree root. %H A076292 Amiram Eldar, <a href="/A076292/b076292.txt">Table of n, a(n) for n = 1..10000</a> %F A076292 A025478(a(n)) = A007947(a(n)). %e A076292 A001597(17) = 144 = (3*2^2)^2 is not a term. %t A076292 q[n_] := n == 1 || Length[(u = Union[FactorInteger[n][[;;,2]]])] == 1 && u[[1]] > 1; Select[Range[2000], q] (* _Amiram Eldar_, Jan 01 2022 *) %o A076292 (PARI) is(n)=n==1 || (ispower(n,,&n) && issquarefree(n)) \\ _Charles R Greathouse IV_, Oct 16 2015 %Y A076292 Cf. A001597, A025478, A005117, A007947, A072777. %K A076292 nonn %O A076292 1,2 %A A076292 _Reinhard Zumkeller_, Nov 06 2002