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 A354258 #9 May 22 2022 00:02:14 %S A354258 1,3,9,16,25,36,49,32,27,75,121,144,169,147,225,64,289,108,361,400, %T A354258 441,363,529,288,125,507,81,784,841,900,961,128,1089,867,1225,432, %U A354258 1369,1083,1521,800,1681,1764,1849,1936,675,1587,2209,576,343,375,2601,2704 %N A354258 Earliest occurrence of n in A354257. %C A354258 a(n) is odd if and only if n is odd or n == 2, 10 (mod 12). %C A354258 a(n) = n^2 if and only if: (a) n is odd or n == 6 (mod 12), and n is squarefree; or (b) n is 4 times an odd squareefree number. %H A354258 Jianing Song, <a href="/A354258/b354258.txt">Table of n, a(n) for n = 1..10000</a> %F A354258 a(n) = n * rad(n) if n is odd or n == 6 (mod 12); (3/4) * n * rad(n) if n == 2, 10 (mod 12); 2 * n * rad(n) if n is divisible by 4, where rad = A007947. %o A354258 (PARI) rad(n) = factorback(factorint(n)[, 1]); %o A354258 a(n) = n*rad(n)*if(n%2 || n%12==6, 1, if(n%12==2 || n%12==10, 3/4, 2)) %Y A354258 Cf. A354257, A007947, A354270. %K A354258 nonn,easy %O A354258 1,2 %A A354258 _Jianing Song_, May 21 2022