login
A204252
Permanent of the n-th principal submatrix of A201208 (in square format).
1
1, 5, 18, 132, 876, 8820, 85392, 1106496, 14057280, 223560000, 3513456000, 66305952000, 1241430624000, 27127003680000, 589395356928000, 14638710417408000, 362021985626112000, 10073602372700160000, 279369787588448256000, 8609476463579013120000, 264609942011693752320000
OFFSET
1,2
MATHEMATICA
f[i_, j_] := 1 + Mod[i + j, 2];
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}]] (* A201208 in square format *)
Permanent[m_] :=
With[{a = Array[x, Length[m]]},
Coefficient[Times @@ (m.a), Times @@ a]];
Table[Permanent[m[n]], {n, 1, 20}] (* A204252 *)
CROSSREFS
Cf. A201208.
Sequence in context: A009365 A140296 A278172 * A281564 A291356 A091059
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jan 14 2012
EXTENSIONS
a(20)-a(21) from Pontus von Brömssen, Mar 03 2024
STATUS
approved