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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A258920 Number of (n+2) X (3+2) 0..1 arrays with no 3 x 3 subblock diagonal sum equal to the antidiagonal sum or central row sum equal to the central column sum. 1
1680, 1936, 1200, 1024, 1440, 1600, 1568, 1936, 2560, 2704, 2592, 3136, 4000, 4096, 3872, 4624, 5760, 5776, 5408, 6400, 7840, 7744, 7200, 8464, 10240, 10000, 9248, 10816, 12960, 12544, 11552, 13456, 16000, 15376, 14112, 16384, 19360, 18496, 16928 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) - 3*a(n-2) + 4*a(n-3) - 2*a(n-4) + 2*a(n-6) - 4*a(n-7) + 3*a(n-8) - 2*a(n-9) + a(n-10) for n>13.
Empirical g.f.: 16*x*(105 - 89*x + 148*x^2 - 143*x^3 - 87*x^4 + 54*x^5 - 148*x^6 + 171*x^7 + 11*x^8 + 39*x^9 + 4*x^10 - 22*x^11 - 25*x^12) / ((1 - x)^3*(1 + x)*(1 + x^2)^3). - Colin Barker, Dec 23 2018
EXAMPLE
Some solutions for n=4:
..1..1..0..0..1....0..0..0..1..1....0..0..1..1..1....1..0..0..0..0
..1..0..1..0..0....0..0..0..0..1....0..0..0..0..1....0..0..1..1..1
..0..0..1..0..1....0..1..1..1..1....1..1..1..1..0....0..0..0..1..1
..1..0..0..1..0....0..0..1..1..1....1..1..0..0..0....1..1..1..1..0
..1..0..1..1..0....1..1..1..0..0....0..1..1..0..1....0..1..1..1..1
..0..1..0..1..1....1..1..1..1..0....0..1..0..1..1....1..1..0..0..1
CROSSREFS
Column 3 of A258921.
Sequence in context: A156425 A247853 A093787 * A268288 A175749 A231548
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 14 2015
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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 24 10:37 EDT 2024. Contains 374583 sequences. (Running on oeis4.)