157286400domain: NAppears in sequencesa(n)=(-1)^(n+1)*det(M(n)) where M(n) is the n X n matrix M(i,j)=min(abs(i-j),i).at n=26A080692(1/4) times the sum of the elements of all subsets of [n] whose sum is divisible by four.at n=24A309296