A251023 Number of (n+1)X(3+1) 0..3 arrays with no 2X2 subblock having the sum of its diagonal elements greater than the maximum of its antidiagonal elements

1966, 8207, 20608, 51347, 118871, 272547, 608267, 1356939, 3017800, 6755296, 15194024, 34402203, 78257659, 178761713, 409448316, 939731942, 2159479782, 4966624315, 11428488961, 26305947749, 60561558048, 139440168208

Offset

1,1

Comments

Column 3 of A251028

Links

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

Formula

Empirical: a(n) = 8*a(n-1) -25*a(n-2) +35*a(n-3) -7*a(n-4) -49*a(n-5) +77*a(n-6) -55*a(n-7) +20*a(n-8) -3*a(n-9) for n>14

Example

Some solutions for n=4
..0..0..3..3....0..0..2..2....0..0..2..3....0..0..1..2....3..3..3..3
..1..0..0..0....0..0..0..0....1..0..1..0....0..0..1..1....0..0..0..0
..1..0..0..0....1..0..0..0....1..0..1..0....0..0..0..0....2..1..1..1
..2..1..1..1....1..0..0..0....1..0..1..0....0..0..0..0....2..0..0..0
..3..0..0..0....2..1..0..0....3..2..1..0....3..2..2..1....3..1..1..0

Crossrefs

Sequence in context: A253528 A235966 A252380 * A193312 A202596 A239185

Adjacent sequences: A251020 A251021 A251022 * A251024 A251025 A251026

Keyword

nonn

Author

R. H. Hardin, Nov 29 2014

Status

approved