A237968 Number of (n+1)X(2+1) 0..3 arrays with the upper median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one

1494, 10014, 59014, 357672, 2270776, 14222512, 88114176, 550642732, 3451069630, 21560822458, 134629301012, 841895591970, 5264528244482, 32900378176060, 205627745431856, 1285545369352008, 8036253217579508, 50230256232200120

Offset

1,1

Comments

Column 2 of A237974

Links

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

Formula

Empirical: a(n) = 84*a(n-3) +773*a(n-4) +1372*a(n-5) +3600*a(n-6) -8931*a(n-7) -55854*a(n-8) -94782*a(n-9) -31846*a(n-10) +191731*a(n-11) +369506*a(n-12) +355656*a(n-13) +149556*a(n-14) +448480*a(n-15) +642040*a(n-16) +99840*a(n-17) for n>20

Example

Some solutions for n=3
..2..1..0....1..1..0....0..3..0....0..2..1....3..1..2....3..2..0....1..1..0
..1..2..1....1..3..2....1..2..3....1..0..3....0..1..2....2..3..1....2..3..1
..1..1..2....0..2..3....0..1..0....2..3..2....0..0..0....0..1..1....3..0..2
..2..3..3....0..1..0....2..3..1....3..1..1....3..1..0....1..2..2....2..1..0

Crossrefs

Sequence in context: A367769 A171617 A067841 * A062912 A328975 A345527

Adjacent sequences: A237965 A237966 A237967 * A237969 A237970 A237971

Keyword

nonn

Author

R. H. Hardin, Feb 16 2014

Status

approved