%I #18 May 05 2021 01:54:30
%S 1,2,3,4,6,8,9,10,12,16,18,20,24,27,30,32,36,40,42,48,50,54,60,64,72,
%T 80,81,84,90,96,100,108,110,120,126,128,136,144,150,156,160,162,168,
%U 180,192,200,210,216,220,240,243,250,252,256,270,272,288,294,300,312,320,324,330,336
%N Numbers k that divide 19^k-1.
%H Seiichi Manyama, <a href="/A333506/b333506.txt">Table of n, a(n) for n = 1..10000</a>
%t Join[{1}, Select[Range[2, 336], PowerMod[19, #, #] == 1 &]] (* _Amiram Eldar_, May 05 2021 *)
%o (PARI) for(k=1, 1e3, if(Mod(19, k)^k==1, print1(k", ")))
%Y Columns k=19 of A333432.
%Y Cf. A128358, A128360, A128399.
%K nonn
%O 1,2
%A _Seiichi Manyama_, Mar 25 2020