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 A139733 #16 Sep 08 2022 08:45:33
%S A139733 0,1,17,217,2465,26281,7153,588665,9492289,118985033,265558929,
%T A139733 5611255833,7551629537,342842572777,886559899441,29969271650489,
%U A139733 164170328587905,914583003869833,5979447221143249,53815024990289241,628450412988459041,7961896726109825321
%N A139733 9^n mod 8^n.
%H A139733 Vincenzo Librandi, <a href="/A139733/b139733.txt">Table of n, a(n) for n = 0..1000</a>
%p A139733 seq(9^n mod 8^n, n=1..100); # _Robert Israel_, Aug 03 2014
%t A139733 Table[PowerMod[9, n, 8^n], {n, 0, 40}] (* _Vincenzo Librandi_, Aug 03 2014 *)
%o A139733 (Magma) [9^n mod 8^n: n in [0..25]]; // _Vincenzo Librandi_, Jun 04 2011
%K A139733 nonn
%O A139733 0,3
%A A139733 _N. J. A. Sloane_, May 20 2008