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A204439
Symmetric matrix: f(i,j)=((i+j+2)^2 mod 3), by (constant) antidiagonals.
3
1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
OFFSET
1
COMMENTS
A block matrix over {0,1}. For guides to related matrices and permanents, see A204435 and A204263.
EXAMPLE
Northwest corner:
1 1 0 1 1 0
1 0 1 1 0 1
0 1 1 0 1 1
1 1 0 1 1 0
1 0 1 1 0 1
0 1 1 0 1 1
MATHEMATICA
f[i_, j_] := Mod[(2 + i + j)^2, 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, 14}, {i, 1, n}]] (* A204439 *)
Permanent[m_] :=
With[{a = Array[x, Length[m]]},
Coefficient[Times @@ (m.a), Times @@ a]];
Table[Permanent[m[n]], {n, 1, 22}] (* A204440 *)
CROSSREFS
Sequence in context: A284512 A267253 A261178 * A204443 A105349 A096606
KEYWORD
nonn,tabl
AUTHOR
Clark Kimberling, Jan 15 2012
STATUS
approved