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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A280961 T(n,k)=Number of nXk 0..2 arrays with no element equal to more than one of its horizontal, vertical and antidiagonal neighbors and with new values introduced in order 0 sequentially upwards. 7

%I #4 Jan 11 2017 15:17:43

%S 1,2,2,4,9,4,11,42,42,11,30,205,241,205,30,82,997,1554,1554,997,82,

%T 224,4850,9899,14106,9899,4850,224,612,23593,63085,126267,126267,

%U 63085,23593,612,1672,114769,402077,1121528,1599234,1121528,402077,114769,1672,4568

%N T(n,k)=Number of nXk 0..2 arrays with no element equal to more than one of its horizontal, vertical and antidiagonal neighbors and with new values introduced in order 0 sequentially upwards.

%C Table starts

%C ....1.......2.........4.........11...........30............82...........224

%C ....2.......9........42........205..........997..........4850.........23593

%C ....4......42.......241.......1554.........9899.........63085........402077

%C ...11.....205......1554......14106.......126267.......1121528.......9986376

%C ...30.....997......9899.....126267......1599234......20029500.....251270618

%C ...82....4850.....63085....1121528.....20029500.....346289502....6052621154

%C ..224...23593....402077....9986376....251270618....6052621154..148137367471

%C ..612..114769...2562733...88940022...3152475854..105777297118.3624578433814

%C .1672..558298..16334111..791997382..39530438497.1846875100200

%C .4568.2715861.104108376.7052519878.495721552160

%H R. H. Hardin, <a href="/A280961/b280961.txt">Table of n, a(n) for n = 1..112</a>

%F Empirical for column k:

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

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

%F k=3: [order 12] for n>16

%F k=4: [order 54] for n>57

%e Some solutions for n=4 k=4

%e ..0..1..2..0. .0..0..1..0. .0..0..1..2. .0..1..0..1. .0..1..0..0

%e ..2..0..1..2. .1..2..0..1. .2..1..0..1. .1..0..2..2. .1..2..1..2

%e ..0..1..0..1. .1..2..1..0. .2..0..1..2. .2..1..0..0. .2..1..2..1

%e ..2..0..2..2. .0..0..2..2. .1..2..0..0. .2..1..2..2. .0..0..1..0

%Y Column 1 is A021006(n-3).

%K nonn,tabl

%O 1,2

%A _R. H. Hardin_, Jan 11 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.

Last modified March 3 00:46 EST 2024. Contains 370499 sequences. (Running on oeis4.)