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 A088666 #17 Sep 08 2022 08:45:12
%S A088666 1,2,7,2,7,6,7,2,7,2,1,2,7,2,7,6,7,2,7,2,1,2,7,2,7,6,7,2,7,2,1,2,7,2,
%T A088666 7,6,7,2,7,2,1,2,7,2,7,6,7,2,7,2,1,2,7,2,7,6,7,2,7,2,1,2,7,2,7,6,7,2,
%U A088666 7,2,1,2,7,2,7,6,7,2,7,2,1,2,7,2,7,6,7,2,7,2
%N A088666 a(n) = (n^4 + 1) mod 10.
%C A088666 Periodic, with period 10. - _Harvey P. Dale_, Jan 31 2015
%H A088666 Harvey P. Dale, <a href="/A088666/b088666.txt">Table of n, a(n) for n = 0..1000</a>
%H A088666 <a href="/index/Rec#order_10">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 1).
%F A088666 a(n) = A010879(A002523(n)). - _Michel Marcus_, Feb 01 2015
%t A088666 PowerMod[Range[0,90],4,10]+1 (* or *) PadRight[{},100,{1,2,7,2,7,6,7,2,7,2}] (* _Harvey P. Dale_, Jan 31 2015 *)
%t A088666 LinearRecurrence[{0, 0, 0, 0, 0, 0, 0, 0, 0, 1},{1, 2, 7, 2, 7, 6, 7, 2, 7, 2},90] (* _Ray Chandler_, Aug 26 2015 *)
%o A088666 (Magma) [(n^4+1) mod 10: n in [0..100]]; // _Vincenzo Librandi_, Feb 01 2015
%Y A088666 Cf. A010879 (n mod 10), A002523 (n^4+1).
%K A088666 easy,nonn
%O A088666 0,2
%A A088666 _Cino Hilliard_, Nov 23 2003
%E A088666 Edited by _Don Reble_, May 03 2006
%E A088666 Name clarified by _Vincenzo Librandi_, Feb 01 2015