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 A204694 #26 Aug 06 2018 16:50:51
%S A204694 1,1,4,3,0,5,0,7,0,1,0,3,0,5,0,7,0,1,0,3,0,5,0,7,0,1,0,3,0,5,0,7,0,1,
%T A204694 0,3,0,5,0,7,0,1,0,3,0,5,0,7,0,1,0,3,0,5,0,7,0,1,0,3,0,5,0,7,0,1,0,3,
%U A204694 0,5,0,7,0,1,0,3,0,5,0,7,0,1,0,3,0,5,0
%N A204694 a(n) = n^n (mod 8).
%C A204694 Eventually periodic with period 8 = A174824(8): a(1)=1, a(2)=4 and repeat [3, 0, 5, 0, 7, 0, 1, 0].
%H A204694 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 0, 0, 0, 0, 1).
%F A204694 G.f.: (4*x^10 + x^8 - 7*x^7 - 5*x^5 - 3*x^3 - 4*x^2 - x - 1)/(x^8 - 1). - _Chai Wah Wu_, Jun 04 2016
%F A204694 a(n) = A000312(n) mod 8. - _Michel Marcus_, Jun 04 2016
%t A204694 Table[PowerMod[n,n,8], {n,0,100}]
%t A204694 Join[{1, 1, 4},LinearRecurrence[{0, 0, 0, 0, 0, 0, 0, 1},{3, 0, 5, 0, 7, 0, 1, 0},84]] (* _Ray Chandler_, Aug 25 2015 *)
%t A204694 PadRight[{1,1,4},120,{0,1,0,3,0,5,0,7}] (* _Harvey P. Dale_, Aug 06 2018 *)
%o A204694 (PARI) a(n)=lift(Mod(n,8)^n) \\ _Charles R Greathouse IV_, Jan 23 2012
%Y A204694 Cf. A000312, A174824.
%K A204694 nonn,easy
%O A204694 0,3
%A A204694 _José María Grau Ribas_, Jan 18 2012