A253320 - OEIS

A253320

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

44, 126, 377, 848, 2042, 4218, 9228, 18482, 38621, 76654, 156631, 310658, 627864, 1247558, 2507954, 4993614, 10012411, 19968402, 39986317, 79836334, 159770246, 319221314, 638635272, 1276539506, 2553459769, 5105272678, 10211298371

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Column 2 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)

EXAMPLE

Some solutions for n=4

..1..0..1....0..1..0....0..1..0....1..0..1....1..0..1....0..0..0....1..0..0

..0..1..0....0..0..0....0..0..0....0..0..0....0..0..0....0..1..1....0..0..1

..1..0..1....0..1..0....1..0..1....0..1..0....0..1..0....1..1..1....1..0..1

..0..1..0....1..1..1....0..1..0....0..0..0....1..1..1....1..1..1....0..1..0

..1..0..1....1..1..1....1..1..1....1..1..1....0..1..0....1..1..1....0..1..1

CROSSREFS

Sequence in context: A044295 A044676 A253327 * A230829 A358818 A183642

Adjacent sequences: A253317 A253318 A253319 * A253321 A253322 A253323

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 30 2014

STATUS

approved