A181280 Number of 4Xn binary matrices M with rows in strictly increasing order and rows of M*Mtranspose (mod 2) in strictly decreasing order.

0, 0, 0, 58, 1629, 28924, 507052, 8211776, 133693904, 2140571200, 34361115072, 549587348992, 8798356254976, 140744002571264, 2252082614856704, 36030315649662976, 576487656686899200, 9223539637335310336

Offset

1,4

Comments

Row 4 of A181274

Links

R. H. Hardin, Table of n, a(n) for n=1..27

M. Kauers and C. Koutschan, Some D-finite and some possibly D-finite sequences in the OEIS, arXiv:2303.02793 [cs.SC], 2023.

Formula

a(n) = (1/3)*2^(2*n-11)*(6*n^2-219*n+820) - (1/9)*2^(n-5)*(3*n+32) - (113/3)*(-1)^n*2^(3*n-14) + 2^(4*n-9) - (1/3)*(-1)^n*2^(2*n-11)*(13*n-164) +(1/9)*2^(3*n-14)*(288*n-3473) (conjectured). - Manuel Kauers and Christoph Koutschan, Mar 02 2023

Example

M and M*Mtranspose (mod 2) for 4X5:
  0  1  0  1  1      1  0  0  0
  1  0  0  0  0      0  1  1  1
  1  1  0  0  1      0  1  1  0
  1  1  1  1  0      0  1  0  0

Crossrefs

Sequence in context: A184599 A160347 A358795 * A017774 A035724 A017721

Adjacent sequences: A181277 A181278 A181279 * A181281 A181282 A181283

Keyword

nonn

Author

R. H. Hardin, Oct 10 2010

Status

approved