A237636 Number of (n+1)X(7+1) 0..2 arrays with the upper median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one

30656, 16448, 4132, 5976, 7756, 11984, 18344, 23968, 35732, 47936, 71426, 95872, 140200, 191744, 286672, 383488, 560800, 766976, 1146688, 1533952, 2243200, 3067904, 4586752, 6135808, 8972800, 12271616, 18347008, 24543232, 35891200

Offset

1,1

Comments

Column 7 of A237637

Links

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

Formula

Empirical: a(n) = 4*a(n-4) for n>15

Example

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

Crossrefs

Sequence in context: A234791 A134118 A235853 * A236126 A236944 A269828

Adjacent sequences: A237633 A237634 A237635 * A237637 A237638 A237639

Keyword

nonn

Author

R. H. Hardin, Feb 10 2014

Status

approved