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!)
A283630 Number of nX4 0..1 arrays with no 1 equal to more than one of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly two elements. 1
1, 36, 639, 7742, 85469, 856710, 8209582, 75625580, 677582140, 5935472812, 51063145445, 432757594342, 3621630322984, 29983493956274, 245931204265827, 2000828493677966, 16161824873357957, 129718958313978310 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 4 of A283634.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 18*a(n-1) -78*a(n-2) -186*a(n-3) +1365*a(n-4) +234*a(n-5) -4523*a(n-6) +15594*a(n-7) +6057*a(n-8) -60614*a(n-9) +66588*a(n-10) +51762*a(n-11) -313536*a(n-12) +181776*a(n-13) +367095*a(n-14) -650452*a(n-15) +214245*a(n-16) +853410*a(n-17) -640177*a(n-18) -457782*a(n-19) +317076*a(n-20) +100568*a(n-21) -60480*a(n-22) -7680*a(n-23) +4096*a(n-24)

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Cf. A283634.

Sequence in context: A010952 A323980 A287990 * A035713 A035478 A250624

Adjacent sequences: A283627 A283628 A283629 * A283631 A283632 A283633

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 12 2017

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 January 30 09:35 EST 2023. Contains 359943 sequences. (Running on oeis4.)