The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A236271 Number of (n+1) X (1+1) 0..2 arrays with the upper median unequal to the lower median in every 2 X 2 subblock. 1
 42, 208, 1048, 5328, 27168, 138720, 708640, 3620768, 18501536, 94542752, 483118496, 2468772768, 12615641504, 64467060640, 329432556960, 1683430581152, 8602485031328, 43959490084768, 224637040795040, 1147915959163808 (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) + 4*a(n-2) - 16*a(n-3) - 8*a(n-4). Empirical g.f.: 2*x*(21 - x - 80*x^2 - 36*x^3) / ((1 - 2*x)*(1 - 3*x - 10*x^2 - 4*x^3)). - Colin Barker, Oct 21 2018 EXAMPLE Some solutions for n=5: ..1..0....1..0....2..1....1..0....0..1....0..2....1..2....1..2....2..1....0..2 ..0..1....2..0....0..2....2..0....0..2....2..1....0..2....0..2....1..2....1..2 ..0..2....1..2....2..0....2..0....2..1....1..2....0..2....1..2....0..0....2..1 ..0..2....2..0....1..0....0..2....0..0....0..2....2..0....1..2....2..2....2..1 ..1..0....1..2....1..0....0..2....2..2....2..0....1..0....0..0....0..1....0..0 ..2..0....0..0....1..0....2..0....1..0....1..2....1..0....1..2....2..0....2..1 CROSSREFS Column 1 of A236278. Sequence in context: A299056 A299817 A236278 * A008446 A255424 A122232 Adjacent sequences:  A236268 A236269 A236270 * A236272 A236273 A236274 KEYWORD nonn AUTHOR R. H. Hardin, Jan 21 2014 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.

Last modified June 15 08:06 EDT 2021. Contains 345048 sequences. (Running on oeis4.)