A206747 Number of (n+1) X 4 0..3 arrays with every 2 X 3 or 3 X 2 subblock having an equal number of clockwise and counterclockwise edge increases.

15680, 793152, 43894936, 2475217568, 140074119984, 7932406245672, 449274384195312, 25446640113989392, 1441291246284432152, 81634472380414712320, 4623762855908451472048, 261889171309065224583560

Offset

1,1

Comments

Column 3 of A206752.

Links

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

Formula

Empirical: a(n) = 115*a(n-1) -4680*a(n-2) +94092*a(n-3) -1008017*a(n-4) +4943715*a(n-5) +6216049*a(n-6) -219040623*a(n-7) +1137239832*a(n-8) -1770376686*a(n-9) -6357529459*a(n-10) +35013840779*a(n-11) -55315099594*a(n-12) -30038280332*a(n-13) +243181370778*a(n-14) -350008700828*a(n-15) +104582198472*a(n-16) +298190627632*a(n-17) -432780191652*a(n-18) +257764861416*a(n-19) -65113822320*a(n-20) -1255722624*a(n-21) +3297112384*a(n-22) -318728448*a(n-23).

Example

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

Crossrefs

Sequence in context: A253173 A195814 A165612 * A075043 A109567 A075050

Adjacent sequences: A206744 A206745 A206746 * A206748 A206749 A206750

Keyword

nonn

Author

R. H. Hardin, Feb 12 2012

Status

approved