login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A261107 Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00010001 00010101 or 01010101. 1
33, 52, 106, 206, 402, 790, 1546, 3026, 5928, 11610, 22736, 44526, 87200, 170774, 334446, 654980, 1282716, 2512082, 4919682, 9634740, 18868742, 36952682, 72368406, 141726816, 277558826, 543573226, 1064537776, 2084798554, 4082884696 (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) = a(n-1) +2*a(n-3) +2*a(n-4) +2*a(n-5) +a(n-6) for n>7.

Empirical g.f.: x*(33 + 19*x + 54*x^2 + 34*x^3 + 26*x^4 + 6*x^5 - 5*x^6) / (1 - x - 2*x^3 - 2*x^4 - 2*x^5 - x^6). - Colin Barker, Dec 30 2018

EXAMPLE

Some solutions for n=4:

..1..0..1..0....1..0..1..0....0..1..0..1....0..1..0..0....1..0..1..0

..0..1..0..0....0..1..0..0....1..0..0..0....1..0..1..0....0..1..0..1

..1..0..1..0....1..0..1..0....0..1..0..1....0..0..0..1....1..0..1..0

..0..1..0..1....0..1..0..1....1..0..1..0....1..0..1..0....0..0..0..1

..0..0..1..0....0..0..1..0....0..1..0..1....0..1..0..1....1..0..1..0

..0..1..0..1....0..1..0..0....1..0..0..0....1..0..1..0....0..1..0..1

CROSSREFS

Column 2 of A261113.

Sequence in context: A014976 A109407 A204374 * A211141 A007373 A229254

Adjacent sequences:  A261104 A261105 A261106 * A261108 A261109 A261110

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 08 2015

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 20 09:12 EDT 2019. Contains 324234 sequences. (Running on oeis4.)