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 A068919 #15 Sep 25 2017 12:56:05 %S A068919 6,10,14,21,22,26,30,34,38,39,42,46,55,57,58,62,66,70,74,78,82,86,93, %T A068919 94,102,105,106,110,111,114,118,122,129,130,134,138,142,146,154,155, %U A068919 158,165,166,170,174,178,182,183,186,190,194,195,201,202,203,205,206 %N A068919 Squarefree orders of non-Abelian groups. %C A068919 This set is the difference A005117 \ A003277, that is, the squarefree numbers that are not cyclic (A003277). - _Jeppe Stig Nielsen_, Sep 25 2017 %H A068919 Reinhard Zumkeller, <a href="/A068919/b068919.txt">Table of n, a(n) for n = 1..10000</a> %t A068919 Complement[Select[Range[206], SquareFreeQ[#] &], %t A068919 Select[Range[206], FiniteGroupCount[#] == 1 &]] (* _Geoffrey Critzer_, Nov 28 2015 *) %o A068919 (Haskell) %o A068919 a068919 n = a068919_list !! (n-1) %o A068919 a068919_list = filter ((== 1) . a008966) a056868_list %o A068919 -- _Reinhard Zumkeller_, Jun 28 2013 %o A068919 (PARI) is(n)=issquarefree(n)&&gcd(n,eulerphi(n))!=1 \\ _Jeppe Stig Nielsen_, Sep 25 2017 %Y A068919 Intersection of A060652 and A005117. %Y A068919 Cf. A064899. %Y A068919 Also intersection of A056868 and A005117. - _Reinhard Zumkeller_, Jun 28 2013 %Y A068919 Cf. A008966. %K A068919 nonn %O A068919 1,1 %A A068919 Sharon Sela (sharonsela(AT)hotmail.com), Mar 29 2002