A236324 - OEIS

A236324

Number of (n+1) X (2+1) 0..1 arrays colored with the sum of the upper and lower median values of each 2 X 2 subblock.

32, 44, 60, 92, 156, 236, 332, 524, 860, 1276, 1852, 2956, 4716, 6956, 10364, 16540, 25820, 38188, 57996, 91980, 141468, 210748, 323964, 509388, 776620, 1166956, 1805244, 2814172, 4273436, 6473068, 10035148, 15530124, 23566812, 35927420

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OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = a(n-3) + 4*a(n-4) for n>5.

Empirical g.f.: 4*x*(8 + 11*x + 15*x^2 + 15*x^3 - 4*x^4) / (1 - x^3 - 4*x^4). - Colin Barker, Oct 21 2018

EXAMPLE

Some solutions for n=5:

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

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

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

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

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

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

CROSSREFS

Sequence in context: A229115 A035112 A308765 * A211813 A353234 A303959

Adjacent sequences: A236321 A236322 A236323 * A236325 A236326 A236327

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 22 2014

STATUS

approved