A253400 - OEIS

A253400

Number of (n+1)X(1+1) 0..2 arrays with every 2X2 subblock diagonal maximum plus antidiagonal minimum unequal to its neighbors horizontally, vertically and ne+sw antidiagonally

81, 480, 2890, 17560, 106540, 646240, 3920448, 23781448, 144267352, 875147104, 5308894208, 32204831776, 195362700680, 1185113825256, 7189187420440, 43611271279904, 264556337839152, 1604860554179552, 9735463002163768

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

OFFSET

1,1

COMMENTS

Column 1 of A253407

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) +24*a(n-2) +7*a(n-3) -15*a(n-4) -84*a(n-6) -139*a(n-7) -28*a(n-8) -14*a(n-9) -24*a(n-10) for n>11

EXAMPLE

Some solutions for n=4

..2..0....1..0....0..1....0..0....0..2....1..2....0..0....0..0....1..2....2..2

..0..1....2..0....0..0....1..2....0..0....0..1....2..1....2..1....2..2....2..2

..2..0....0..1....2..2....0..1....2..1....2..1....0..1....1..1....1..0....0..0

..1..2....2..0....2..0....2..1....1..0....1..2....2..0....1..1....2..0....2..1

..2..1....2..2....2..0....2..2....0..2....1..1....2..0....2..2....0..2....2..1

CROSSREFS

Sequence in context: A205293 A205286 A253407 * A250620 A237082 A236651

Adjacent sequences: A253397 A253398 A253399 * A253401 A253402 A253403

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 31 2014

STATUS

approved