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!)
A280440 T(n,k)=Number of nXk 0..1 arrays with no element equal to more than one of its horizontal and vertical neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards. 7

%I #4 Jan 03 2017 07:04:51

%S 0,0,0,1,4,1,2,10,10,2,5,20,21,20,5,10,38,42,42,38,10,20,68,77,80,77,

%T 68,20,38,120,136,138,138,136,120,38,71,208,236,232,225,232,236,208,

%U 71,130,358,404,386,360,360,386,404,358,130,235,612,687,640,574,548,574,640,687

%N T(n,k)=Number of nXk 0..1 arrays with no element equal to more than one of its horizontal and vertical neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

%C Table starts

%C ...0...0....1....2....5...10...20...38...71..130...235...420...744..1308..2285

%C ...0...4...10...20...38...68..120..208..358..612..1042..1768..2992..5052..8514

%C ...1..10...21...42...77..136..236..404..687.1162..1959..3294..5528..9262.15497

%C ...2..20...42...80..138..232..386..640.1062.1764..2934..4884..8134.13548.22562

%C ...5..38...77..138..225..360..574..920.1487.2422..3971..6542.10814.17914.29713

%C ..10..68..136..232..360..548..834.1284.2008.3188..5128..8332.13638.22436.37032

%C ..20.120..236..386..574..834.1211.1784.2684.4128..6478.10334.16693.27208.44620

%C ..38.208..404..640..920.1284.1784.2512.3620.5360..8152.12692.20136.32400.52660

%C ..71.358..687.1062.1487.2008.2684.3620.4989.7078.10365.15642.24224.38290.61451

%C .130.612.1162.1764.2422.3188.4128.5360.7078.9604.13474.19576.29384.45340.71490

%H R. H. Hardin, <a href="/A280440/b280440.txt">Table of n, a(n) for n = 1..568</a>

%F Empirical for column k:

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

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

%F k=3: a(n) = 3*a(n-1) -a(n-2) -3*a(n-3) +a(n-4) +a(n-5) for n>6

%F k=4: a(n) = 4*a(n-1) -4*a(n-2) -2*a(n-3) +4*a(n-4) -a(n-6) for n>7

%F k=5: a(n) = 4*a(n-1) -4*a(n-2) -2*a(n-3) +4*a(n-4) -a(n-6) for n>7

%F k=6: a(n) = 4*a(n-1) -4*a(n-2) -2*a(n-3) +4*a(n-4) -a(n-6) for n>7

%F k=7: a(n) = 4*a(n-1) -4*a(n-2) -2*a(n-3) +4*a(n-4) -a(n-6) for n>7

%e Some solutions for n=4 k=4

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

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

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

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

%Y Column 1 is A001629(n-1).

%Y Column 2 is A279262.

%K nonn,tabl

%O 1,5

%A _R. H. Hardin_, Jan 03 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 24 00:30 EDT 2024. Contains 371917 sequences. (Running on oeis4.)