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!)
A262421 Number of (2+1) X (n+1) 0..1 arrays with each row divisible by 3 and column not divisible by 3, read as a binary number with top and left being the most significant bits. 1
5, 4, 45, 114, 709, 2892, 15293, 72370, 367125, 1808844, 9078925, 45214674, 226307429, 1130307532, 5653140573, 28257215730, 141297157045, 706426855884, 3532211260205, 17660645718034, 88303765183749, 441515959527372 (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) = 5*a(n-1) + 12*a(n-2) - 60*a(n-3) - 39*a(n-4) + 195*a(n-5) + 28*a(n-6) - 140*a(n-7).

Empirical g.f.: x*(5 - 21*x - 35*x^2 + 141*x^3 + 34*x^4 - 140*x^5) / ((1 - x)*(1 + x)*(1 - 2*x)*(1 + 2*x)*(1 - 5*x)*(1 - 7*x^2)). - Colin Barker, Dec 31 2018

EXAMPLE

Some solutions for n=4:

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

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

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

CROSSREFS

Row 2 of A262420.

Sequence in context: A189748 A304151 A223527 * A305170 A192344 A181613

Adjacent sequences:  A262418 A262419 A262420 * A262422 A262423 A262424

KEYWORD

nonn

AUTHOR

R. H. Hardin, Sep 22 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 2 14:00 EDT 2021. Contains 346424 sequences. (Running on oeis4.)