%I #6 Jul 12 2012 00:39:59

%S 1,18,457,23672,1894385,222366990,35787014405,7577453436556,

%T 2041650829418725,682219727134076250,276875111860035807025,

%U 134154122874807259146080,76495123111877275062902585,50706144718387731766299555750

%N Permanent of the n-th principal submatrix of A204158.

%t f[i_, j_] := Max[3 i - 2 j, 3 j - 2 i];

%t m[n_] := Table[f[i, j], {i, 1, n}, {j, 1, n}]

%t TableForm[m[8]] (* 8x8 principal submatrix *)

%t Flatten[Table[f[i, n + 1 - i],

%t {n, 1, 12}, {i, 1, n}]] (* A204158 *)

%t Table[Det[m[n]], {n, 1, 22}] (* A204240 *)

%t Permanent[m_] :=

%t With[{a = Array[x, Length[m]]},

%t Coefficient[Times @@ (m.a), Times @@ a]];

%t Table[Permanent[m[n]], {n, 1, 14}] (* A204241 *)

%Y Cf. A204158, A204240.

%K nonn

%O 1,2

%A _Clark Kimberling_, Jan 13 2012