The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A221899 Number of 2 X n arrays of occupancy after each element stays put or moves to some horizontal, vertical or antidiagonal neighbor, without move-in move-out straight through or left turns. 1

%I

%S 3,31,258,2241,19408,167960,1453952,12585637,108943526,943035150,

%T 8163084148,70661144632,611655753520,5294603734144,45831055372945,

%U 396721972412987,3434097733826959,29726176177614458,257315201439500033

%N Number of 2 X n arrays of occupancy after each element stays put or moves to some horizontal, vertical or antidiagonal neighbor, without move-in move-out straight through or left turns.

%C Row 2 of A221898.

%H R. H. Hardin, <a href="/A221899/b221899.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 5*a(n-1) + 26*a(n-2) + 45*a(n-3) + 34*a(n-4) - 2*a(n-5) - 4*a(n-6) + a(n-7).

%F Empirical g.f.: x*(3 + 16*x + 25*x^2 + 10*x^3 - 2*x^4 - 4*x^5 + x^6) / (1 - 5*x - 26*x^2 - 45*x^3 - 34*x^4 + 2*x^5 + 4*x^6 - x^7). - _Colin Barker_, Aug 11 2018

%e Some solutions for n=3:

%e ..0..2..3....0..0..0....0..3..0....2..0..2....1..1..2....0..4..1....1..2..1

%e ..1..0..0....3..2..1....2..0..1....2..0..0....0..2..0....0..1..0....0..1..1

%Y Cf. A221898.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 30 2013

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 1 04:36 EST 2022. Contains 358454 sequences. (Running on oeis4.)