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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A183445 Number of n X 4 binary arrays with every 1 having exactly two king-move neighbors equal to 1. 1
 1, 13, 30, 72, 283, 831, 2399, 7761, 23840, 72396, 225569, 696929, 2144537, 6635889, 20510002, 63318408, 195704391, 604826763, 1868678179, 5774848073, 17846507936, 55148861000, 170427655945, 526681961257, 1627610746225, 5029867948101 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Column 4 of A183450. LINKS R. H. Hardin, Table of n, a(n) for n = 1..200 FORMULA Empirical: a(n) = 3*a(n-1) + a(n-2) + 5*a(n-3) - 18*a(n-4) - 16*a(n-5) + 7*a(n-6) + 3*a(n-7) + a(n-8) - a(n-9). Empirical g.f.: x*(1 + x)*(1 + 9*x - 19*x^2 - 17*x^3 + 7*x^4 + 3*x^5 + x^6 - x^7) / (1 - 3*x - x^2 - 5*x^3 + 18*x^4 + 16*x^5 - 7*x^6 - 3*x^7 - x^8 + x^9). - Colin Barker, Mar 29 2018 EXAMPLE Some solutions for 5 X 4: ..0..1..0..0....1..1..0..0....0..1..1..0....0..1..0..0....0..0..1..0 ..1..0..1..0....0..1..0..0....0..0..1..0....1..1..0..0....0..1..1..0 ..1..0..1..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0 ..0..1..0..0....1..1..0..0....0..1..0..0....0..1..0..0....1..0..0..0 ..0..0..0..0....0..1..0..0....1..1..0..0....0..1..1..0....1..1..0..0 CROSSREFS Cf. A183450. Sequence in context: A139577 A172463 A329950 * A296124 A299130 A156532 Adjacent sequences: A183442 A183443 A183444 * A183446 A183447 A183448 KEYWORD nonn AUTHOR R. H. Hardin, Jan 04 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 31 12:47 EDT 2023. Contains 363066 sequences. (Running on oeis4.)