A253986 Number of (n+2)X(1+2) 0..1 arrays with every 3X3 subblock diagonal median plus antidiagonal median nondecreasing horizontally, vertically and ne-to-sw antidiagonally

512, 2736, 11872, 51856, 222400, 914112, 3644672, 14254784, 54856896, 208045808, 779267488, 2888373904, 10608724864, 38652879616, 139832334592, 502668749632, 1796764701568, 6389654104112, 22617698170848, 79723311240208

Offset

1,1

Comments

Column 1 of A253993

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 8*a(n-1) -21*a(n-2) +30*a(n-3) -44*a(n-4) -60*a(n-5) +252*a(n-6) -140*a(n-7) +446*a(n-8) +340*a(n-9) -1082*a(n-10) +32*a(n-11) -1048*a(n-12) -844*a(n-13) +1800*a(n-14) +548*a(n-15) +215*a(n-16) +324*a(n-17) -293*a(n-18) -54*a(n-19) -24*a(n-21) +16*a(n-22)

Example

Some solutions for n=4
..0..1..1....0..1..0....0..0..0....0..1..0....1..0..0....0..0..0....0..1..1
..1..1..1....0..1..1....0..1..0....0..0..0....0..0..0....1..1..1....0..0..1
..1..0..1....1..1..0....0..0..0....1..0..0....1..0..0....0..0..1....1..0..1
..1..1..1....1..1..0....1..1..0....0..0..0....0..1..1....1..1..1....1..1..1
..0..0..1....0..0..1....1..1..1....1..0..0....0..1..0....1..1..1....1..1..0
..1..0..1....0..0..1....1..1..0....1..0..0....0..0..1....1..0..1....0..1..0

Crossrefs

Sequence in context: A254505 A253993 A258910 * A250826 A250504 A250820

Adjacent sequences: A253983 A253984 A253985 * A253987 A253988 A253989

Keyword

nonn

Author

R. H. Hardin, Jan 21 2015

Status

approved