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A204432 Permanent of the n-th principal submatrix of A204431.

%I A204432 #6 Jul 12 2012 00:39:59
%S A204432 2,1,9,40,132,1032,7824,51912,530712,5619456,53529984,707802624,
%T A204432 9591229440,119716185600,1938416832000,32061464064000,496487584512000,
%U A204432 9509523337728000,185772505605120000,3434389946233344000
%N A204432 Permanent of the n-th principal submatrix of A204431.
%t A204432 f[i_, j_] := Mod[2 i + 2 j + 1, 3];
%t A204432 m[n_] := Table[f[i, j], {i, 1, n}, {j, 1, n}]
%t A204432 TableForm[m[8]] (* 8x8 principal submatrix *)
%t A204432 Flatten[Table[f[i, n + 1 - i],
%t A204432   {n, 1, 14}, {i, 1, n}]]        (* A204431 *)
%t A204432 Permanent[m_] :=
%t A204432   With[{a = Array[x, Length[m]]},
%t A204432    Coefficient[Times @@ (m.a), Times @@ a]];
%t A204432 Table[Permanent[m[n]], {n, 1, 22}]  (* A204432 *)
%Y A204432 Cf. A204231, A204263.
%K A204432 nonn
%O A204432 1,1
%A A204432 _Clark Kimberling_, Jan 15 2012