A204256 Permanent of the n-th principal submatrix of A204255.

1, 3, 19, 86, 1060, 13276, 215308, 3086544, 68937280, 1552257216, 40750688448, 987692033664, 31883024335104, 1036810188322560, 37597332892066560, 1285416947916933120, 54309158991453634560, 2309262618253981040640, 106842526312699253145600

Offset

0,2

Links

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

Mathematica

f[i_, j_] := 1 + Mod[i + j, 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, 12}, {i, 1, n}]]  (* A204255 *)
Join[{1}, Table[Permanent[m[n]], {n, 1, 20}]]    (* A204256 *)

Prog

(PARI) a(n) = matpermanent(matrix(n, n, i, j, 1 + ((i+j) % 4))); \\ Michel Marcus, Jan 30 2021

Crossrefs

Cf. A204255.

Sequence in context: A163431 A167242 A089621 * A015528 A183384 A050863

Adjacent sequences: A204253 A204254 A204255 * A204257 A204258 A204259

Keyword

nonn

Author

Clark Kimberling, Jan 14 2012

Extensions

a(0) and a(18) from Pontus von Brömssen, Jan 30 2021

Status

approved