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A204428 Permanent of the n-th principal submatrix of A204427.

%I A204428 #6 Jul 12 2012 00:39:59
%S A204428 2,4,9,40,192,1032,7824,62496,530712,5619456,61710336,707802624,
%T A204428 9591229440,133983590400,1938416832000,32061464064000,544216485888000,
%U A204428 9509523337728000,185772505605120000,3711395156281344000
%N A204428 Permanent of the n-th principal submatrix of A204427.
%t A204428 f[i_, j_] := Mod[2 i + j + 2, 3];
%t A204428 m[n_] := Table[f[i, j], {i, 1, n}, {j, 1, n}]
%t A204428 TableForm[m[8]] (* 8x8 principal submatrix *)
%t A204428 Flatten[Table[f[i, n + 1 - i],
%t A204428   {n, 1, 14}, {i, 1, n}]]        (* A204427 *)
%t A204428 Permanent[m_] :=
%t A204428   With[{a = Array[x, Length[m]]},
%t A204428    Coefficient[Times @@ (m.a), Times @@ a]];
%t A204428 Table[Permanent[m[n]], {n, 1, 22}] (* A204428 *)
%Y A204428 Cf. A204227, A204263.
%K A204428 nonn
%O A204428 1,1
%A A204428 _Clark Kimberling_, Jan 15 2012