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 A256575 #46 Apr 21 2018 17:41:31 %S A256575 315,420,495,525,585,630,660,735,765,780,819,825,840,855,945,975,990, %T A256575 1020,1035,1050,1071,1092,1140,1170,1260,1275,1287,1320,1380,1425, %U A256575 1428,1470,1485,1530,1540,1560,1575,1638,1650,1665,1680,1683,1710,1716,1725,1755,1815,1820,1827,1845,1881,1890,1911,1925 %N A256575 Nonsquarefree orders of cyclotomic polynomials containing a coefficient with an absolute value greater than one. %C A256575 Numbers in A013590 that are not squarefree. %o A256575 (PARI) is(n)=if (!issquarefree(n), for(k=0, n, if(abs(polcoeff(polcyclo(n), k))>1, return(n))); 0) %o A256575 for(n=1, 10^4, if(is(n), print1(n, ", "))) \\ edited by _Michel Marcus_, Apr 21 2018 %Y A256575 Cf. A013590, A013595. %K A256575 nonn %O A256575 1,1 %A A256575 _Derek Orr_, Apr 22 2015