login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

T(n,k)=Number of nXk integer arrays with each element equal to the number of horizontal, vertical and antidiagonal neighbors less than or equal to itself.
5

%I #4 Dec 19 2015 09:18:18

%S 1,3,3,2,8,2,7,50,50,7,19,1491,150,1491,19,35,7741,5582,5582,7741,35,

%T 77,82424,59454,1111758,59454,82424,77,176,763505,809199,74291246,

%U 74291246,809199,763505,176,377,6210500,12253344,4880049141,16816210911

%N T(n,k)=Number of nXk integer arrays with each element equal to the number of horizontal, vertical and antidiagonal neighbors less than or equal to itself.

%C Table starts

%C ...1.......3.........2..............7.................19..................35

%C ...3.......8........50...........1491...............7741...............82424

%C ...2......50.......150...........5582..............59454..............809199

%C ...7....1491......5582........1111758...........74291246..........4880049141

%C ..19....7741.....59454.......74291246........16816210911.......3057992438196

%C ..35...82424....809199.....4880049141......3057992438196....1826477943263851

%C ..77..763505..12253344...389508194942....853715037314662.1718918677426337400

%C .176.6210500.172499046.27699226366664.203178594217817141

%H R. H. Hardin, <a href="/A265965/b265965.txt">Table of n, a(n) for n = 1..83</a>

%F Empirical for column k:

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

%F k=2: [order 41]

%e Some solutions for n=3 k=4

%e ..0..4..1..2....2..2..3..1....0..3..3..1....1..4..0..2....0..2..1..0

%e ..2..1..6..0....0..6..0..4....2..6..0..4....0..2..6..1....3..6..5..3

%e ..3..2..1..2....2..2..4..0....2..1..4..0....3..3..1..2....1..0..2..0

%Y Column 1 is A196537.

%K nonn,tabl

%O 1,2

%A _R. H. Hardin_, Dec 19 2015