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 A216833 #22 Feb 25 2019 04:36:23
%S A216833 2,6,4,6,18,10,12,12,8,18,6,22,20,54,28,10,30,12,36,12,20,14,36,46,42,
%T A216833 24,52,20,18,58,60,18,12,66,66,70,18,60,30,78,162,82,8,84,22,12,30,36,
%U A216833 48,90,100,102,12,106,36,36,28,44,36,24,110,60,100,14,42
%N A216833 Multiplicative order of 2 mod 3*(2n-1).
%C A216833 a(n) is the smallest m such that 3*(2n-1) | (2^m+1).
%H A216833 Muniru A Asiru, <a href="/A216833/b216833.txt">Table of n, a(n) for n = 1..10000</a>
%F A216833 a(n) = 2*A216829(n).
%t A216833 Table[MultiplicativeOrder[2, 3*(2*n-1)], {n, 100}] (* _T. D. Noe_, Sep 19 2012 *)
%o A216833 (PARI) vector(100,n,znorder(Mod(2,3*(2*n-1)))) \\ _Joerg Arndt_, Sep 14 2012.
%o A216833 (GAP) List([1..70],n->OrderMod(2,3*(2*n-1))); # _Muniru A Asiru_, Feb 25 2019
%Y A216833 Cf. A003558, A002326, A216469, A216829.
%K A216833 nonn
%O A216833 1,1
%A A216833 _V. Raman_, Sep 17 2012