cp's OEIS Frontend

A231746 T(n,k)=Number of nXk 0..3 arrays with no element less than a strict majority of its horizontal and vertical neighbors.

%I A231746 #6 Jul 23 2025 06:39:38
%S A231746 4,4,4,16,84,16,50,318,318,50,144,1328,4430,1328,144,422,6064,60806,
%T A231746 60806,6064,422,1268,26918,784076,2154900,784076,26918,1268,3823,
%U A231746 116909,9945132,71742015,71742015,9945132,116909,3823,11472,511264,126926437
%N A231746 T(n,k)=Number of nXk 0..3 arrays with no element less than a strict majority of its horizontal and vertical neighbors.
%C A231746 Table starts
%C A231746 ....4......4.........16............50..............144..................422
%C A231746 ....4.....84........318..........1328.............6064................26918
%C A231746 ...16....318.......4430.........60806...........784076..............9945132
%C A231746 ...50...1328......60806.......2154900.........71742015...........2426463539
%C A231746 ..144...6064.....784076......71742015.......6425495277.........598711367728
%C A231746 ..422..26918....9945132....2426463539.....598711367728......155985773478611
%C A231746 .1268.116909..126926437...82701946547...56006640316980....40539474933206048
%C A231746 .3823.511264.1625269595.2814528154294.5220406326242670.10471241201508754882
%H A231746 R. H. Hardin, <a href="/A231746/b231746.txt">Table of n, a(n) for n = 1..111</a>
%F A231746 Empirical for column k:
%F A231746 k=1: a(n) = 4*a(n-1) -6*a(n-2) +10*a(n-3) -5*a(n-4) +6*a(n-5) -a(n-6) +a(n-7) for n>8
%F A231746 k=2: [order 19] for n>20
%F A231746 k=3: [order 87] for n>88
%e A231746 Some solutions for n=3 k=4
%e A231746 ..0..2..0..0....3..1..1..2....0..2..1..0....0..0..2..2....1..1..3..1
%e A231746 ..0..3..0..3....3..1..0..0....0..0..0..0....1..0..0..3....3..1..1..1
%e A231746 ..0..1..0..0....3..1..0..0....0..3..3..1....3..1..0..0....0..0..0..0
%Y A231746 Column 1 is A203094 for n>1
%K A231746 nonn,tabl
%O A231746 1,1
%A A231746 _R. H. Hardin_, Nov 13 2013