login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A238173 Number of (n+1) X (1+1) 0..2 arrays with the maximum plus the minimum of every 2 X 2 subblock equal. 1
81, 423, 2329, 13447, 79641, 479703, 2918233, 17859079, 109676409, 674920407, 4158200569, 25636328263, 158116883673, 975438912855, 6018376002073, 37135707651847, 229151775103929, 1414053340986711, 8725990453989049 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 10*a(n-1) - 22*a(n-2) - 20*a(n-3) + 63*a(n-4) - 6*a(n-5) - 24*a(n-6).

Empirical g.f.: x*(81 - 387*x - 119*x^2 + 1083*x^3 - 234*x^4 - 456*x^5) / ((1 - x)*(1 - 3*x - 2*x^2)*(1 - 6*x - 3*x^2 + 12*x^3)). - Colin Barker, Oct 24 2018

EXAMPLE

Some solutions for n=5:

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

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

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

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

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

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

CROSSREFS

Column 1 of A238180.

Sequence in context: A206414 A205979 A206661 * A206407 A236610 A236704

Adjacent sequences:  A238170 A238171 A238172 * A238174 A238175 A238176

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 19 2014

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 January 25 10:10 EST 2022. Contains 350565 sequences. (Running on oeis4.)