A204552 Permanent of the n-th principal submatrix of A204551.

1, 2, 8, 75, 1157, 23974, 655636, 24625600, 1208111716, 71223596496, 5012804515680, 428588572904208, 43766538817494528, 5110290596191238784, 679891748332818756096, 104076096896467882616832, 18184550626132306514989056, 3531069898673803414239744000

Offset

1,2

Links

Table of n, a(n) for n=1..18.

Mathematica

f[i_, j_] :=
Floor[(2 i + 2 j + 1)/4] - Floor[(i + j)/4];
m[n_] := Table[f[i, j], {i, 1, n}, {j, 1, n}]
TableForm[m[16]] (* 8x8 principal submatrix *)
Flatten[Table[f[i, n + 1 - i],
  {n, 1, 14}, {i, 1, n}]]    (* A204551 *)
Permanent[m_] :=
  With[{a = Array[x, Length[m]]},
   Coefficient[Times @@ (m.a), Times @@ a]];
Table[Permanent[m[n]], {n, 1, 15}]  (* A204552 *)

Crossrefs

Cf. A204551.

Sequence in context: A295373 A356746 A132039 * A396988 A002668 A193205

Adjacent sequences: A204549 A204550 A204551 * A204553 A204554 A204555

Keyword

nonn

Author

Clark Kimberling, Jan 16 2012

Extensions

a(16)-a(18) from Pontus von Brömssen, Jun 22 2025

Status

approved