A213696 Half the number of (n+1)X(n+1) symmetric 0..7 arrays with no 2X2 subblock summing to 14

240, 105856, 342943680, 8159542628448, 1425762604012263360, 1829651398830137742302620

Offset

1,1

Comments

Column 7 of A213697

Links

Table of n, a(n) for n=1..6.

Example

Some solutions for n=4
..0..0..7..0..4....4..0..7..0..1....0..2..3..7..0....0..4..1..2..0
..0..1..5..1..7....0..1..2..4..2....2..1..2..3..2....4..3..3..4..5
..7..5..4..7..2....7..2..6..1..4....3..2..7..5..1....1..3..0..5..2
..0..1..7..4..4....0..4..1..7..6....7..3..5..1..0....2..4..5..1..5
..4..7..2..4..3....1..2..4..6..2....0..2..1..0..7....0..5..2..5..0

Crossrefs

Sequence in context: A052263 A218514 A270054 * A275459 A377220 A035281

Adjacent sequences: A213693 A213694 A213695 * A213697 A213698 A213699

Keyword

nonn

Author

R. H. Hardin Jun 18 2012

Status

approved