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A204253
Symmetric matrix given by f(i,j)=1+[(i+j) mod 3].
2
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, 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, 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
OFFSET
1,1
EXAMPLE
Northwest corner:
3 1 2 3 1 2 3 1
1 2 3 1 2 3 1 2
2 3 1 2 3 1 2 3
3 1 2 3 1 2 3 1
1 2 3 1 2 3 1 2
2 3 1 2 3 1 2 3
MATHEMATICA
f[i_, j_] := 1 + Mod[i + j, 3];
m[n_] := Table[f[i, j], {i, 1, n}, {j, 1, n}]
TableForm[m[8]] (* 8x8 principal submatrix *)
Flatten[Table[f[i, n + 1 - i],
{n, 1, 12}, {i, 1, n}]] (* A204253 *)
Permanent[m_] :=
With[{a = Array[x, Length[m]]},
Coefficient[Times @@ (m.a), Times @@ a]];
Table[Permanent[m[n]], {n, 1, 20}] (* A204254 *)
CROSSREFS
Cf. A204254.
Sequence in context: A175636 A352935 A364757 * A064048 A336218 A016464
KEYWORD
nonn,tabl
AUTHOR
Clark Kimberling, Jan 14 2012
STATUS
approved