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 A066608 #15 Dec 07 2024 14:55:40
%S A066608 0,0,64,0,399,208,1978,0,6265,8576,6978,1792,19075,22864,36199,0,
%T A066608 17089,87616,31867,107776,83791,142928,195688,225280,201999,302656,
%U A066608 362152,304896,401393,546976,612688,0,226279,629152,399674,718336,1132463
%N A066608 a(n) = 4^n mod n^4.
%H A066608 Harry J. Smith, <a href="/A066608/b066608.txt">Table of n, a(n) for n = 1..1000</a>
%e A066608 a(7) = 1978 as 4^7 = 16384 = (7^4)*6 + 1978.
%t A066608 Table[PowerMod[4,n,n^4],{n,50}] (* _Harvey P. Dale_, Aug 25 2023 *)
%o A066608 (PARI) a(n) = { lift(Mod(4, n^4)^n) } \\ _Harry J. Smith_, Mar 11 2010
%Y A066608 Cf. A066606.
%K A066608 easy,nonn
%O A066608 1,3
%A A066608 _Amarnath Murthy_, Dec 22 2001
%E A066608 More terms from _Floor van Lamoen_ and _Robert G. Wilson v_, Dec 23 2001