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 A211995 #37 Sep 09 2018 02:28:53
%S A211995 0,1,0,2,6,13,46,33,246,479,398,883,20,6215,9467,16751,42245,115091,
%T A211995 140675,492363,674695,1312859,2497856,2451041,4384342,6956591,
%U A211995 24348068,118772672,147268896,112787953,394757837,844781520,809251672,2832380853,1323398395,13221828975
%N A211995 a(n) = floor(7^n / 2^n) mod 2^n.
%C A211995 Conjectured to be always positive for n > 2.
%D A211995 Lew Baxter, Exponential Diophantine Equations, post to NmbrThry list, Oct 25 2012
%t A211995 Table[Mod[Floor[7^n/2^n], 2^n], {n, 0, 29}] (* _Alonso del Arte_, Oct 25 2012 *)
%o A211995 (PARI) a(n)=7^n\2^n%2^n
%o A211995 (Maxima) A211995(n):=mod(floor( 7^n / 2^n ), 2^n); makelist(A211995(n),n,0,30); /* _Martin Ettl_, Oct 25 2012 */
%Y A211995 Cf. A000079, A094970.
%K A211995 nonn
%O A211995 0,4
%A A211995 _M. F. Hasler_, Oct 25 2012