A210071 1/4 the number of (n+1)X3 0..3 arrays with every 2X2 subblock having one or three distinct clockwise edge differences

313, 7653, 183628, 4437262, 107248254, 2593403383, 62718516080, 1516857228897, 36686107681359, 887282513364238, 21459693101245663, 519021821704689384, 12553011852527384605, 303605996524472486222, 7342987441944334048364

Offset

1,1

Comments

Column 2 of A210077

Links

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

Formula

Empirical: a(n) = 40*a(n-1) -410*a(n-2) +162*a(n-3) +13887*a(n-4) -37312*a(n-5) -114069*a(n-6) +441850*a(n-7) +251010*a(n-8) -1865698*a(n-9) +353991*a(n-10) +3283497*a(n-11) -1672828*a(n-12) -2287997*a(n-13) +1529824*a(n-14) +444317*a(n-15) -334882*a(n-16) -35990*a(n-17) +21286*a(n-18) +648*a(n-19) -288*a(n-20)

Example

Some solutions for n=4
..1..1..3....3..2..0....0..3..1....3..0..0....1..1..3....0..1..1....0..0..3
..2..1..1....1..1..3....0..3..1....1..2..1....0..1..1....2..1..2....2..0..3
..1..1..3....0..1..2....0..0..2....3..3..3....0..1..0....2..1..0....1..3..3
..2..3..3....1..1..0....2..0..0....2..1..1....0..1..1....3..1..0....1..1..1
..1..3..1....0..1..0....0..0..0....2..1..1....0..0..0....2..1..0....0..0..0

Crossrefs

Sequence in context: A272442 A200912 A123059 * A327636 A332131 A287294

Adjacent sequences: A210068 A210069 A210070 * A210072 A210073 A210074

Keyword

nonn

Author

R. H. Hardin Mar 17 2012

Status

approved