A204447 - OEIS

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A204447

Symmetric matrix: f(i,j)=floor[(i+j+5)/4]-floor[(i+j+2)/4], by (constant) antidiagonals.

0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 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, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 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, 0, 1, 1, 1, 1, 1, 1, 1, 1

(list; table; graph; refs; listen; history; text; internal format)

OFFSET

COMMENTS

A block matrix over {0,1}. For guides to related matrices and permanents, see A204435 and A204263.

LINKS

Table of n, a(n) for n=1..99.

EXAMPLE

Northwest corner:

0 1 1 1 0 1 1 1

1 1 1 0 1 1 1 0

1 1 0 1 1 1 0 1

1 0 1 1 1 0 1 1

0 1 1 1 0 1 1 1

1 1 1 0 1 1 1 0

1 1 0 1 1 1 0 1

1 0 1 1 1 0 1 1

MATHEMATICA

f[i_, j_] :=

Floor[(i + j + 5)/4] - Floor[(i + j + 2)/4];

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}]] (* A204447 *)

Permanent[m_] :=

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

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

Table[Permanent[m[n]], {n, 1, 22}] (* A204448 *)

CROSSREFS

Cf. A204448, A204435.

Sequence in context: A164980 A252372 A168182 * A368905 A188642 A168046

Adjacent sequences: A204444 A204445 A204446 * A204448 A204449 A204450

KEYWORD

nonn,tabl

AUTHOR

Clark Kimberling, Jan 15 2012

STATUS

approved