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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A221687 Number of n X 2 arrays of occupancy after each element stays put or moves to some king-move neighbor, without consecutive moves in the same direction. 1
 3, 35, 396, 4429, 49387, 550264, 6129659, 68277335, 760519092, 8471140593, 94356794511, 1051003927840, 11706726309807, 130396694392883, 1452438312980628, 16178148223958949, 180202131485051219 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 2 of A221688. LINKS R. H. Hardin, Table of n, a(n) for n = 1..23 FORMULA Empirical: a(n) = 13*a(n-1) - 18*a(n-2) - 29*a(n-3) - 15*a(n-4) - 12*a(n-5) - 2*a(n-6). Empirical g.f.: x*(3 - 4*x - 5*x^2 - 2*x^3 - 2*x^4) / (1 - 13*x + 18*x^2 + 29*x^3 + 15*x^4 + 12*x^5 + 2*x^6). - Colin Barker, Aug 10 2018 EXAMPLE Some solutions for n=3: ..0..0....2..0....0..0....0..1....0..0....1..1....0..0....0..1....1..1....2..0 ..2..4....1..2....3..2....3..1....3..2....2..0....6..0....2..2....2..0....0..4 ..0..0....0..1....0..1....0..1....1..0....0..2....0..0....0..1....2..0....0..0 CROSSREFS Cf. A221688. Sequence in context: A089933 A086043 A221774 * A221223 A006767 A065929 Adjacent sequences: A221684 A221685 A221686 * A221688 A221689 A221690 KEYWORD nonn AUTHOR R. H. Hardin, Jan 22 2013 STATUS approved

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 June 22 23:47 EDT 2024. Contains 373629 sequences. (Running on oeis4.)