A204561 - OEIS

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

%S 1,3,26,274,4409,100776,3348056,134046480,6730452660,416113787472,

%T 32085045507600,2844782901384192,294773230519886592,

%U 35411618960849142144,4970308923985374563328,778808458472330553255936

%N Permanent of the n-th principal submatrix of A204560.

%t f[i_, j_] :=

%t Floor[(2 i + 2 j + 4)/4] - Floor[(i + j + 2)/4];

%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, 14}, {i, 1, n}]]     (* A204560 *)

%t Permanent[m_] :=

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

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

%t Table[Permanent[m[n]], {n, 1, 15}]  (* A204561 *)

%Y Cf. A204560, A204551.

%K nonn

%O 1,2

%A _Clark Kimberling_, Jan 16 2012