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!)
A185460 Number of (n+1) X 3 binary arrays with no 2 X 2 subblock determinant equal to any horizontal or vertical neighbor 2 X 2 subblock determinant. 1
34, 92, 240, 672, 1646, 4452, 11050, 29506, 74092, 195978, 496142, 1303446, 3318830, 8676824, 22183736, 57796628, 148199862, 385159228, 989675770, 2567545726, 6607214940, 17119703570, 44102038206, 114168385010, 294332423078 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A185467.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n) = 5*a(n-2) + 4*a(n-3) + 4*a(n-4) - 8*a(n-5) - a(n-6) + 3*a(n-8) for n>10.

Empirical g.f.: 2*x*(17 + 46*x + 35*x^2 + 38*x^3 - 29*x^4 + 18*x^5 - 29*x^6 - 7*x^7 - 18*x^8 + 2*x^9) / (1 - 5*x^2 - 4*x^3 - 4*x^4 + 8*x^5 + x^6 - 3*x^8). - Colin Barker, Apr 15 2018

EXAMPLE

Some solutions for 5 X 3:

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

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

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

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

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

CROSSREFS

Cf. A185467.

Sequence in context: A067977 A183311 A282811 * A260467 A202421 A202414

Adjacent sequences:  A185457 A185458 A185459 * A185461 A185462 A185463

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 28 2011

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 March 28 15:12 EDT 2020. Contains 333089 sequences. (Running on oeis4.)