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 A103335 #16 Feb 16 2025 08:32:56 %S A103335 1,2,41,109,151,229,251,271,313,337,362,367,409,439,542,626,674,733, %T A103335 761,818,878,971,991,1021,1031,1069,1289,1297,1303,1429,1471,1489, %U A103335 1681,1759,1783,1789,1811,1871,1873,1879,2062,2137,2342,2411,2441,2551,2594 %N A103335 Numbers whose smallest primitive root (A046145) is not prime. %H A103335 Robert Israel, <a href="/A103335/b103335.txt">Table of n, a(n) for n = 1..10000</a> %H A103335 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PrimitiveRoot.html">Primitive Root.</a> %p A103335 filter:= proc(n) %p A103335 local r; %p A103335 r:= numtheory:-primroot(n); %p A103335 r <> FAIL and not isprime(r) %p A103335 end proc: %p A103335 filter(1):= true: %p A103335 select(filter, [$1..3000]); _Robert Israel_, Sep 08 2020 %t A103335 L = {}; Do[ If[!PrimeQ[ Min[ Select[ Range[n], CoprimeQ[#, n] && MultiplicativeOrder[#, n] == CarmichaelLambda[n] &]]], %t A103335 L = Append[L, n]], {n, 1, 3000}]; L (* _Jonathan Sondow_, May 17 2017 *) %Y A103335 Cf. A001918, A046144, A046145, A046146, A103309, A103310, A103336, A103337, A103338. %K A103335 nonn %O A103335 1,2 %A A103335 _Harry J. Smith_, Jan 31 2005 %E A103335 Offset changed by _Robert Israel_, Sep 08 2020