%I
%S 2,18,4,70,882,32,182,29718,1068,500,5604,4030,8890182,
%T 776,1744,113582,4832118,1118,1111225770,1764132,11018,
%U 20000849130,23156,71011068,16432,2205718,8920484118,1063532
%N A179071 for p == 1 (mod 4).
%C It appears that a(n) is negative and even. (Added Aug 28 2011: This conjecture has been proved by Maxim Vsemirnov.)
%H M. Vsemirnov, <a href="http://arxiv.org/abs/1108.4031">On R. Chapman's "evil determinant": case p == 1 (mod 4)</a>, arXiv preprint arXiv:1108.4031 [math.NT], 20112012.
%t a71[p_] := Module[{k}, k = (p1)/2; Det @ Table[JacobiSymbol[ji, p], {i, 1, k+1}, {j, 1, k+1}]];
%t a71 /@ Select[Range[1, 301, 4], PrimeQ] (* _JeanFrançois Alcover_, Dec 05 2018 *)
%Y Cf. A179071, A179072, A179074.
%K sign
%O 1,1
%A _Jonathan Sondow_ and _Wadim Zudilin_, Jun 29 2010
