// 2007-02-24
q:=2^20;
e:=75;
f:=(q-1) div e;
Z:=Integers();
K<a>:=GF(q);
a^20+a^10+a^9+a^7+a^6+a^5+a^4+a+1 eq 0;
b:=a^e;
w:=-1;
chi:=function(a) return w^(Z!Trace(a)); end function;
g:=[ &+[ chi(a^j*b^i) : i in {0..f-1} ]
   : j in [0..e-1] ];
g eq
   [541,29,29,-67,29,221,-67,-3,29,-67,221,-3,-67,-3,-3,29,29,29,
   -67,29,221,-67,-3,29,-67,221,-3,-67,-3,-3,29,29,29,-67,29,-291,
   -67,-3,29,-67,221,-3,-67,-3,-3,29,29,29,-67,29,221,-67,-3,29,
   -67,-291,-3,-67,-3,-3,29,29,29,-67,29,-291,-67,-3,29,-67,-291,
   -3,-67,-3,-3];
e:=75;
Z:=Integers();
Ze:=Set(Integers(e));
P0:=function(i,j) return g[(Z!(i+j))+1]; end function;
R2:={Ze|0,3,6,9,12};
R3:={Ze|i+25:i in R2};
R4:={Ze|i+50:i in R2};
R1:=Ze diff (R2 join R3 join R4);
{ [ &+[ P0(i,j) : j in R1 ], &+[ P0(i,j) : j in R2 ],
    &+[ P0(i,j) : j in R3 ], &+[ P0(i,j) : j in R4 ] ]
    : i in Ze }
    eq
    {
    [ -820, 273, 273, 273 ],
    [ 204, 273, -239, -239 ],
    [ 204, -239, 273, -239 ],
    [ 204, -239, -239, 273 ]
};