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

 

Logo

Please make a donation to keep the OEIS running. We are now in our 56th year. In the past year we added 10000 new sequences and reached almost 9000 citations (which often say "discovered thanks to the OEIS").
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A204266 Permanent of the n-th principal submatrix of A204123. 1
1, 5, 27, 252, 2369, 36103, 518000, 9756177, 200951191, 4899768134, 113249415026, 3553351288210, 105127854228522, 3433390910771142, 122658122808278570, 4957371400718135098, 191264018429152335168 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..17.

MATHEMATICA

f[i_, j_] := Floor[Max[i, j]/Min[i, j]];

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}]]  (*  A204123 *)

Permanent[m_] :=

  With[{a = Array[x, Length[m]]},

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

Table[Permanent[m[n]], {n, 1, 14}]  (* A204266 *)

CROSSREFS

Cf. A204123.

Sequence in context: A105631 A167019 A230563 * A266204 A300621 A265907

Adjacent sequences:  A204263 A204264 A204265 * A204267 A204268 A204269

KEYWORD

nonn

AUTHOR

Clark Kimberling, Jan 14 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 November 26 09:38 EST 2020. Contains 338639 sequences. (Running on oeis4.)