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!)
A259737 Number of (n+2) X (3+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00010101 or 01010101. 1
42, 74, 190, 374, 792, 1514, 3480, 6542, 14580, 27866, 62700, 118718, 266548, 506810, 1138004, 2160350, 4852180, 9215834, 20694708, 39301214, 88262564, 167620346, 376424388, 714880094, 1605429620, 3048894554, 6846969460, 13003247390 (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) = 2*a(n-2) + 9*a(n-4) + 4*a(n-6) - 6*a(n-8) + 4*a(n-10) for n>11.

Empirical g.f.: 2*x*(21 + 37*x + 53*x^2 + 113*x^3 + 17*x^4 + 50*x^5 + 9*x^6 - 74*x^7 - 8*x^8 + 52*x^9 + 12*x^10) / (1 - 2*x^2 - 9*x^4 - 4*x^6 + 6*x^8 - 4*x^10). - Colin Barker, Dec 26 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

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

CROSSREFS

Column 3 of A259742.

Sequence in context: A043752 A043760 A043769 * A039525 A072326 A068700

Adjacent sequences:  A259734 A259735 A259736 * A259738 A259739 A259740

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jul 04 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 August 11 00:25 EDT 2020. Contains 336403 sequences. (Running on oeis4.)