login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A204267 Symmetric matrix: f(i,j)=(i+j+1 mod 3), by antidiagonals. 3
0, 1, 1, 2, 2, 2, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 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

1,4

COMMENTS

A block matrix over {0,1,2}.  See A204263 for a guide to related matrices and permanents.

LINKS

G. C. Greubel, Table of n, a(n) for the first 100 rows, flattened

EXAMPLE

Northwest corner:

0 1 2 0 1 2

1 2 0 1 2 0

2 0 1 2 0 1

0 1 2 0 1 2

1 2 0 1 2 0

2 0 1 2 0 1

MATHEMATICA

f[i_, j_] := Mod[i + j + 1, 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}]]    (* A204267 *)

Permanent[m_] :=

  With[{a = Array[x, Length[m]]},

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

Table[Permanent[m[n]], {n, 1, 22}]  (* A204268 *)

CROSSREFS

Cf. A204268.

Sequence in context: A180472 A308583 A093315 * A237452 A132784 A180834

Adjacent sequences:  A204264 A204265 A204266 * A204268 A204269 A204270

KEYWORD

nonn,tabl

AUTHOR

Clark Kimberling, Jan 15 2012

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 17 16:41 EST 2021. Contains 340247 sequences. (Running on oeis4.)