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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A257444 Number of (n+2) X (5+2) 0..1 arrays with no 3 x 3 subblock diagonal sum 0 and no antidiagonal sum 3 and no row sum 1 and no column sum 1. 1
65, 68, 77, 89, 107, 134, 173, 230, 314, 437, 617, 881, 1268, 1835, 2666, 3884, 5669, 8285, 12119, 17738, 25973, 38042, 55730, 81653, 119645, 175325, 256928, 376523, 551798, 808676, 1185149, 1736897, 2545523, 3730622, 5467469, 8012942, 11743514 (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) = 2*a(n-1) - a(n-2) + a(n-3) - a(n-4) for n>5.

Empirical g.f.: x*(65 - 62*x + 6*x^2 - 62*x^3 + 3*x^4) / ((1 - x)*(1 - x - x^3)). - Colin Barker, Dec 21 2018

EXAMPLE

Some solutions for n=4:

..1..1..0..1..1..0..1....0..0..0..0..0..0..0....0..0..0..0..0..0..0

..1..1..0..1..1..0..1....1..1..0..1..1..0..1....0..1..1..1..0..1..1

..1..1..0..1..1..0..1....1..1..0..1..1..0..1....0..1..1..1..0..1..1

..1..1..0..1..1..0..1....1..1..0..1..1..0..1....0..0..0..0..0..0..0

..0..0..0..0..0..0..0....0..0..0..0..0..0..0....0..1..1..1..0..1..1

..1..1..0..1..1..0..1....1..1..0..1..1..0..1....0..1..1..1..0..1..1

CROSSREFS

Column 5 of A257447.

Sequence in context: A044875 A174928 A081647 * A045025 A321502 A095547

Adjacent sequences:  A257441 A257442 A257443 * A257445 A257446 A257447

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 23 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 24 16:23 EDT 2021. Contains 347645 sequences. (Running on oeis4.)