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 A263029 #16 Sep 08 2022 08:46:14 %S A263029 25,32,50,55,75,81,96,100,110,115,119,121,128,150,153,160,162,165,176, %T A263029 187,200,203,209,215,220,221,224,230,235,238,242,245,253,256,261,275, %U A263029 287,288,289,295,297,299,300,306,319,323,324,330,335,343,345,355 %N A263029 Numbers n such that A002322(n) + 1 is not a prime, where A002322 is Carmichael lambda. %C A263029 Complement of A263028. %H A263029 Antti Karttunen, <a href="/A263029/b263029.txt">Table of n, a(n) for n = 1..25794</a> %t A263029 Select[Range[1, 400], ! PrimeQ[CarmichaelLambda[#] + 1] &] %o A263029 (Magma) [n: n in [2..400] | not IsPrime(CarmichaelLambda(n)+1)]; %o A263029 (PARI) for(n=1, 1e3, if(isprime((1 + lcm(znstar(n)[2]))) == 0, print1(n", "))) \\ _Altug Alkan_, Oct 12 2015 %Y A263029 Cf. A002322, A263027, A263028. %Y A263029 Positions of zeros in A296077. %Y A263029 Cf. also A039689. %K A263029 nonn,easy %O A263029 1,1 %A A263029 _Vincenzo Librandi_, Oct 12 2015