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!)
A207043 Number of (n+1) X 2 0..2 arrays with every 2 X 3 or 3 X 2 subblock having exactly one clockwise edge increases. 1
81, 150, 441, 1416, 4371, 13386, 41589, 128700, 397335, 1229310, 3802377, 11755344, 36352875, 112421490, 347633853, 1075001508, 3324303039, 10279835430, 31788718257, 98301693240, 303982182099, 940016132634, 2906850556773 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A207050.

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) + a(n-2) + 8*a(n-3) - 2*a(n-4) for n>5.

Empirical g.f.: 3*x*(27 - 4*x + 20*x^2 - 88*x^3 + 20*x^4) / (1 - 2*x - x^2 - 8*x^3 + 2*x^4). - Colin Barker, Jun 17 2018

EXAMPLE

Some solutions for n=4:

  2 0   1 1   0 2   2 1   2 1   0 0   1 0   0 2   2 1   2 1

  2 2   1 0   0 1   1 1   1 1   2 0   0 0   0 0   2 0   0 0

  2 2   2 2   0 1   1 1   1 1   2 2   0 0   0 0   0 0   0 0

  2 0   2 2   0 0   0 1   0 0   2 2   0 2   1 2   0 0   0 1

  0 0   2 0   0 0   0 0   0 0   0 2   0 0   2 2   2 2   0 0

CROSSREFS

Cf. A207050.

Sequence in context: A153259 A207050 A206072 * A206065 A139705 A226643

Adjacent sequences:  A207040 A207041 A207042 * A207044 A207045 A207046

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 14 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 October 19 21:52 EDT 2021. Contains 348095 sequences. (Running on oeis4.)