A204258 Permanent of the n-th principal submatrix of A204257.

1, 1, 7, 54, 346, 3732, 50928, 636288, 10421856, 204446592, 3783985632, 84204904320, 2154137877504, 52813565568000, 1488803964595200, 46983956781312000, 1434084567201792000, 48976637440702464000, 1838658764187353088000, 67159997418955456512000

Offset

0,3

Links

Vaclav Kotesovec, Table of n, a(n) for n = 0..35

Mathematica

f[i_, j_] := 1 + Mod[i + 2 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}]]  (* A204257 *)
Join[{1}, Table[Permanent[m[n]], {n, 1, 20}]]  (* A204258 *)

Prog

(PARI) a(n) = matpermanent(matrix(n, n, i, j, 1 + ((i+2*j) % 3))); \\ Michel Marcus, Jan 30 2021

Crossrefs

Cf. A204257.

Sequence in context: A317689 A116202 A203289 * A081008 A116472 A015562

Adjacent sequences: A204255 A204256 A204257 * A204259 A204260 A204261

Keyword

nonn

Author

Clark Kimberling, Jan 14 2012

Extensions

a(0) and a(19) from Pontus von Brömssen, Jan 30 2021

Status

approved