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 A204253 Symmetric matrix given by f(i,j)=1+[(i+j) mod 3]. 2

%I #6 Mar 30 2012 18:58:08

%S 3,1,1,2,2,2,3,3,3,3,1,1,1,1,1,2,2,2,2,2,2,3,3,3,3,3,3,3,1,1,1,1,1,1,

%T 1,1,2,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,1,1,1,1,1,1,1,1,1,1,1,2,2,

%U 2,2,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,3,1,1,1,1,1,1,1,1

%N Symmetric matrix given by f(i,j)=1+[(i+j) mod 3].

%e Northwest corner:

%e 3 1 2 3 1 2 3 1

%e 1 2 3 1 2 3 1 2

%e 2 3 1 2 3 1 2 3

%e 3 1 2 3 1 2 3 1

%e 1 2 3 1 2 3 1 2

%e 2 3 1 2 3 1 2 3

%t f[i_, j_] := 1 + Mod[i + j, 3];

%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}]] (* A204253 *)

%t Permanent[m_] :=

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

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

%t Table[Permanent[m[n]], {n, 1, 20}] (* A204254 *)

%Y Cf. A204254.

%K nonn,tabl

%O 1,1

%A _Clark Kimberling_, Jan 14 2012

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Last modified December 11 10:50 EST 2023. Contains 367722 sequences. (Running on oeis4.)