function P=negbinproc(n0,k)
global m n
m = 2;
n = n0;

P = zeros(m^n,1);
for xi=1:m^n
  x = i2c(xi);
  P(xi) = (sum(x)==k);
end

%P = P+eps;
%sp = sum(P);
P=P/sum(P);
return