The On-Line Encyclopedia of Integer Sequences (OEIS)

A209508 revision #4

A209508

Half the number of (n+1)X6 0..2 arrays with every 2X2 subblock having two or four distinct clockwise edge differences

729, 11673, 189801, 3102219, 50798448, 832374135, 13642432110, 223616134827, 3665458427859, 60083950172598, 984896234494740, 16144445659742595, 264640335145278948, 4337994781387301094, 71108586231270845148

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Column 5 of A209511

LINKS

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

FORMULA

Empirical: a(n) = 30*a(n-1) -291*a(n-2) +1278*a(n-3) -2901*a(n-4) +3519*a(n-5) -2152*a(n-6) +516*a(n-7)

EXAMPLE

Some solutions for n=4

..0..1..2..0..2..0....1..2..0..1..2..0....1..2..0..1..2..1....1..2..1..2..0..1

..1..2..0..1..0..1....2..0..2..0..1..2....0..1..2..0..1..2....2..1..0..1..2..0

..0..1..2..0..2..0....0..2..0..1..2..1....1..2..1..2..0..1....1..0..1..2..0..1

..2..0..1..2..0..2....1..0..2..0..1..2....2..0..2..0..2..0....0..1..0..1..2..0

..0..1..2..0..2..0....0..1..0..1..2..0....0..1..0..1..0..2....2..0..1..0..1..2

CROSSREFS

Sequence in context: A017499 A269057 A017631 * A016758 A183809 A224004

Adjacent sequences: A209505 A209506 A209507 * A209509 A209510 A209511

KEYWORD

nonn

AUTHOR

R. H. Hardin (rhhardin(AT)att.net) Mar 09 2012

STATUS

approved