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 A343933 #12 May 05 2021 01:54:08
%S A343933 0,1,0,0,2,5,6,4,8,7,0,4,10,3,10,4,12,15,3,4,3,19,2,20,11,3,23,16,15,
%T A343933 1,11,4,1,9,24,12,1,11,36,28,26,41,5,12,20,45,26,4,5,35,16,32,48,45,
%U A343933 23,44,51,23,3,32,29,25,44,4,24,19,64,56,28,29,44,60,54,71,12,24,51,65,55,36,68,21,1,40,38
%N A343933 a(n) = (Sum_{k=1..n} (-k)^k) mod n.
%H A343933 Seiichi Manyama, <a href="/A343933/b343933.txt">Table of n, a(n) for n = 1..10000</a>
%t A343933 a[n_] := Mod[Sum[PowerMod[-k, k, n], {k, 1, n}], n]; Array[a, 100] (* _Amiram Eldar_, May 04 2021 *)
%o A343933 (PARI) a(n) = sum(k=1, n, (-k)^k)%n;
%Y A343933 Cf. A341437, A343930, A343931.
%K A343933 nonn,easy
%O A343933 1,5
%A A343933 _Seiichi Manyama_, May 04 2021