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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A217995 Number of n X 1 arrays of the minimum or maximum value of corresponding elements and their horizontal and vertical neighbors in a random 0..2 n X 1 array. 1
 3, 9, 25, 81, 241, 719, 2181, 6543, 19623, 58983, 176995, 531045, 1593739, 4781741, 14346105, 43041933, 129130449, 387399819, 1162223437, 3486708387, 10460197183, 31380761819, 94142587347, 282428344593, 847286292987, 2541861239481 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 1 of A217999. LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 3*a(n-1) + a(n-2) + 2*a(n-3) - 13*a(n-4) - 7*a(n-5) + 3*a(n-6). Empirical g.f.: x*(3 - 5*x^2 - 9*x^3 - 6*x^4 + 3*x^5) / ((1 - 3*x)*(1 - x^2 - 5*x^3 - 2*x^4 + x^5)). - Colin Barker, Jul 23 2018 EXAMPLE Some solutions for n=3: ..1....2....0....0....2....1....1....1....2....1....0....2....2....0....2....1 ..0....2....2....2....2....2....2....1....0....1....2....0....2....0....1....0 ..1....2....0....1....1....0....2....2....2....0....2....0....0....1....2....0 CROSSREFS Cf. A217999. Sequence in context: A198180 A101786 A354647 * A246653 A192371 A192465 Adjacent sequences: A217992 A217993 A217994 * A217996 A217997 A217998 KEYWORD nonn AUTHOR R. H. Hardin, Oct 17 2012 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 March 26 11:37 EDT 2023. Contains 361549 sequences. (Running on oeis4.)