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!)
A283691 T(n,k) = Number of n X k 0..1 arrays with no 1 equal to more than two of its horizontal, diagonal and antidiagonal neighbors. 13

%I #6 Sep 03 2022 21:13:12

%S 2,4,4,8,16,8,16,49,57,16,32,161,264,209,32,64,548,1521,1525,768,64,

%T 128,1824,8687,15226,8732,2816,128,256,6081,47829,149840,150497,49924,

%U 10329,256,512,20353,268285,1392868,2530461,1489917,285770,37889,512,1024

%N T(n,k) = Number of n X k 0..1 arrays with no 1 equal to more than two of its horizontal, diagonal and antidiagonal neighbors.

%C Table starts

%C ...2......4.......8.........16...........32.............64..............128

%C ...4.....16......49........161..........548...........1824.............6081

%C ...8.....57.....264.......1521.........8687..........47829...........268285

%C ..16....209....1525......15226.......149840........1392868.........13354587

%C ..32....768....8732.....150497......2530461.......39372084........640543058

%C ..64...2816...49924....1489917.....42865601.....1119189256......30968693109

%C .128..10329..285770...14754038....726353972....31815868749....1496646288297

%C .256..37889.1635402..146079023..12304063774...904083654190...72299799564414

%C .512.138980.9359104.1446386879.208447516852.25694926726796.3493423029563345

%H R. H. Hardin, <a href="/A283691/b283691.txt">Table of n, a(n) for n = 1..264</a>

%F Empirical for column k:

%F k=1: a(n) = 2*a(n-1).

%F k=2: a(n) = 3*a(n-1) +2*a(n-2) +2*a(n-3) -a(n-4) -a(n-5).

%F k=3: [order 10].

%F k=4: [order 14].

%F k=5: [order 40].

%F k=6: [order 83].

%F Empirical for row n:

%F n=1: a(n) = 2*a(n-1).

%F n=2: a(n) = 3*a(n-1) +a(n-2) +3*a(n-3) -6*a(n-4) -8*a(n-5).

%F n=3: [order 11].

%F n=4: [order 23].

%F n=5: [order 56].

%e Some solutions for n=4, k=4

%e ..1..0..1..1. .1..0..0..0. .0..0..1..0. .0..0..0..1. .1..0..1..0

%e ..0..0..0..0. .1..0..1..0. .0..0..0..1. .0..0..0..0. .1..0..0..0

%e ..1..1..0..1. .0..1..0..0. .0..0..0..1. .0..1..1..0. .0..0..0..1

%e ..1..0..0..1. .0..1..0..1. .1..0..0..1. .1..0..0..0. .0..0..0..1

%Y Column 1 is A000079.

%Y Column 2 is A283124.

%Y Row 1 is A000079.

%K nonn,tabl

%O 1,1

%A _R. H. Hardin_, Mar 14 2017

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 April 23 10:13 EDT 2024. Contains 371905 sequences. (Running on oeis4.)