A377004 Number of inequivalent 2*n X 8 binary arrays with row sums 4 and column sums n up to row and column permutations.

1, 1, 4, 19, 194, 3144, 65548, 1272696, 21855504, 328629713, 4362818853, 51658865022, 551021529952, 5342121192394, 47446872310092, 388746259849648, 2956322263908194, 20980847841062062, 139630332607991630, 875184633222730558, 5186438905325403553

Offset

0,3

Links

Table of n, a(n) for n=0..20.

Example

The a(2) = 4 inequivalent matrices are:
  [1 1 1 1 0 0 0 0]  [1 1 1 1 0 0 0 0 ]  [1 1 1 1 0 0 0 0]  [1 1 1 1 0 0 0 0]
  [1 1 1 1 0 0 0 0]  [1 1 1 0 1 0 0 0 ]  [1 1 0 0 1 1 0 0]  [1 1 0 0 1 1 0 0]
  [0 0 0 0 1 1 1 1]  [0 0 0 1 0 1 1 1 ]  [0 0 1 1 0 0 1 1]  [0 0 1 0 1 0 1 1]
  [0 0 0 0 1 1 1 1]  [0 0 0 0 1 1 1 1 ]  [0 0 0 0 1 1 1 1]  [0 0 0 1 0 1 1 1]

Crossrefs

Column k=4 of A377007.

Cf. A172555, A377003.

Sequence in context: A126147 A007411 A356287 * A276259 A072879 A112958

Adjacent sequences: A377001 A377002 A377003 * A377005 A377006 A377007

Keyword

nonn

Author

Andrew Howroyd, Oct 12 2024

Status

approved