A176192 - OEIS

%I #4 Dec 18 2015 18:17:25

%S 0,-1,0,0,1,-1,-2,0,0,0,0,0,2,-3,1,0,0,1,4,3,0,0,0,0,0,0,0,0,0,0,0,0,

%T 0,-3,7,-4,0,0,4,3,-1,0,0,0,0,0,1,4,-5,0,0,-5,-9,-4,0,0,0,0,0,0,0,0,0,

%U 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-4,13,-9,0,0,9

%N Det(M) where M is an n X n matrix with M[i,j]=Floor[Log(i+j)]

%t a[n_]:= Det@Floor[Table[Log[i + j], {i, n}, {j, n}]]; Table[a[n], {n, 1, 200}]

%K sign

%O 1,7

%A _José María Grau Ribas_, Apr 11 2010