OFFSET
1,1
COMMENTS
It appears that a(n) is negative and even. (Added Aug 28 2011: This conjecture has been proved by Maxim Vsemirnov.)
LINKS
M. Vsemirnov, On R. Chapman's "evil determinant": case p == 1 (mod 4), arXiv preprint arXiv:1108.4031 [math.NT], 2011-2012.
MATHEMATICA
a71[p_] := Module[{k}, k = (p-1)/2; Det @ Table[JacobiSymbol[j-i, p], {i, 1, k+1}, {j, 1, k+1}]];
a71 /@ Select[Range[1, 301, 4], PrimeQ] (* Jean-François Alcover, Dec 05 2018 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Jonathan Sondow and Wadim Zudilin, Jun 29 2010
STATUS
approved