A253325 Number of (n+1)X(7+1) 0..1 arrays with every 2X2 subblock sum nondecreasing horizontally, vertically and antidiagonally ne-to-sw

3249, 17197, 86922, 185672, 503944, 797324, 1660088, 2516513, 4869987, 7734273, 14919670, 25495092, 49930717, 90999544, 180464019, 343236331, 684939660, 1334617667, 2669247347, 5267675675, 10540870453, 20938024856, 41896374843

Offset

1,1

Comments

Column 7 of A253326

Links

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

Formula

Empirical: a(n) = 4*a(n-1) +2*a(n-2) -26*a(n-3) +16*a(n-4) +62*a(n-5) -70*a(n-6) -62*a(n-7) +109*a(n-8) +14*a(n-9) -76*a(n-10) +16*a(n-11) +20*a(n-12) -8*a(n-13) for n>26

Example

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

Crossrefs

Sequence in context: A265198 A269061 A253332 * A204038 A235412 A048421

Adjacent sequences: A253322 A253323 A253324 * A253326 A253327 A253328

Keyword

nonn

Author

R. H. Hardin, Dec 30 2014

Status

approved