login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A206663 Number of (n+1) X 4 0..2 arrays with every 2 X 2 subblock having the number of clockwise edge increases equal to the number of counterclockwise edge increases in its adjacent leftward and upward neighbors. 1
2286, 17844, 166605, 1637151, 16537155, 170170494, 1770039198, 18532885713, 194818897170, 2052968751492, 21666547077210, 228879866510010, 2419265310522048, 25581340823434362, 270562509737535471 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A206668.

LINKS

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

FORMULA

Empirical: a(n) = 26*a(n-1) -144*a(n-2) -1588*a(n-3) +18637*a(n-4) +5758*a(n-5) -751704*a(n-6) +1840094*a(n-7) +14513664*a(n-8) -65772588*a(n-9) -130792664*a(n-10) +1118371160*a(n-11) +21939840*a(n-12) -11122773609*a(n-13) +12058897820*a(n-14) +67650111988*a(n-15) -135206849805*a(n-16) -242499184542*a(n-17) +791308710878*a(n-18) +391513919157*a(n-19) -2894137633169*a(n-20) +570261077334*a(n-21) +6957579656654*a(n-22) -4843693048003*a(n-23) -10901474451808*a(n-24) +13280426659456*a(n-25) +9886997716394*a(n-26) -21783374723218*a(n-27) -1550353388521*a(n-28) +23200269912687*a(n-29) -8933522230705*a(n-30) -15488045412445*a(n-31) +13388405243555*a(n-32) +4905930909701*a(n-33) -10088874981494*a(n-34) +1430106930020*a(n-35) +4307101996461*a(n-36) -2512129319470*a(n-37) -739394091588*a(n-38) +1427826250529*a(n-39) -246681141171*a(n-40) -495751351484*a(n-41) +199766418707*a(n-42) +120977867459*a(n-43) -65754432424*a(n-44) -21474998274*a(n-45) +14092056596*a(n-46) +1990973380*a(n-47) -1895558392*a(n-48) +92084728*a(n-49) +79134384*a(n-50) -10328256*a(n-51) for n>55.

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Sequence in context: A264256 A236700 A268892 * A247990 A206103 A251302

Adjacent sequences:  A206660 A206661 A206662 * A206664 A206665 A206666

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 11 2012

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 23 21:56 EDT 2021. Contains 345402 sequences. (Running on oeis4.)