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 A319882 #25 Oct 01 2018 03:51:24
%S A319882 0,0,0,3,3,10,16,21,33,54,82,85,103,125,138,165,157,204,267,259,359,
%T A319882 422,471,504,584,564,627,713,628,1053,960,1213,1017,1278,1275,1367,
%U A319882 1522,1671,1661,2118,2038,2005,2242,2330,2234,2418,3194,3112,3126
%N A319882 Number of ordered pairs (i, j) with 0 < i < j < prime(n)/2 such that (i^4 mod prime(n)) > (j^4 mod prime(n)).
%C A319882 Conjecture: Let p be any odd prime, and let t(p) be the number of ordered pairs (i,j) with 0 < i < j < p/2 and (i^4 mod p) > (j^4 mod p). If p is not congruent to 7 modulo 8, then t(p) == floor((p-1)/8) (mod 2). When p == 7 (mod 8), we have t(p) == (p+1)/8 + (h(-p)+1)/2 (mod 2), where h(-p) denotes the class number of the imaginary quadratic field Q(sqrt(-p)).
%C A319882 See also A319311, A319480 and A319894 for similar conjectures.
%H A319882 Zhi-Wei Sun, <a href="/A319882/b319882.txt">Table of n, a(n) for n = 2..1000</a>
%H A319882 Zhi-Wei Sun, <a href="http://arxiv.org/abs/1809.07766">Quadratic residues and related permutations</a>, arXiv:1809.07766 [math.NT], 2018.
%e A319882 a(5) = 3 since prime(5) = 11, and the only ordered pairs (i, j) with 0 < i < j < 11/2 and (i^4 mod 11) > (j^4 mod 11) are (2, 3), (2, 4), (3, 4).
%t A319882 f[k_, p_] := f[k, p] = PowerMod[k, 4, p]; Inv[p_] := Inv[p] = Sum[Boole[f[i, p] > f[j, p]], {j, 2, (p - 1)/2}, {i, 1, j - 1}]; Table[Inv[Prime[n]], {n, 2, 50}]
%Y A319882 Cf. A000040, A000583, A319311, A319480, A319894.
%K A319882 nonn
%O A319882 2,4
%A A319882 _Zhi-Wei Sun_, Sep 30 2018