A235950 Number of (n+1) X (4+1) 0..2 arrays colored with the upper median value of each 2 X 2 subblock.

2584, 2660, 1780, 2356, 3496, 5036, 7320, 11908, 17592, 25318, 36632, 59508, 87944, 126588, 183160, 297540, 439720, 632940, 915800, 1487700, 2198600, 3164700, 4579000, 7438500, 10993000, 15823500, 22895000, 37192500, 54965000, 79117500

Offset

1,1

Links

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

Formula

Empirical: a(n) = 5*a(n-4) for n>14.

Empirical g.f.: 2*x*(1292 + 1330*x + 890*x^2 + 1178*x^3 - 4712*x^4 - 4132*x^5 - 790*x^6 + 64*x^7 + 56*x^8 + 69*x^9 + 16*x^10 - 16*x^11 - 8*x^12 - x^13) / (1 - 5*x^4). - Colin Barker, Oct 20 2018

Example

Some solutions for n=5:
..0..1..2..0..0....1..1..2..0..0....1..0..0..0..2....1..1..0..1..2
..0..0..0..2..1....1..2..1..0..1....2..0..1..2..1....0..0..0..2..0
..2..1..0..1..2....2..0..0..0..2....0..0..2..0..0....0..1..2..1..0
..1..2..0..0..0....1..0..1..2..1....1..2..1..0..1....0..2..0..0..0
..0..1..2..1..0....0..0..2..0..0....2..0..0..0..2....2..1..0..1..2
..0..0..1..2..0....1..2..1..1..0....1..0..1..2..1....0..0..0..2..0

Crossrefs

Column 4 of A235954.

Sequence in context: A236425 A235840 A200711 * A260840 A252310 A236351

Adjacent sequences: A235947 A235948 A235949 * A235951 A235952 A235953

Keyword

nonn

Author

R. H. Hardin, Jan 17 2014

Status

approved