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 A227103 T(n,k)=Number of nXk 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X(k+1) binary array having a sum of two, with rows and columns of the latter in lexicographically nondecreasing order 6

%I

%S 2,4,4,7,15,7,11,48,48,11,16,136,239,136,16,22,341,1084,1084,341,22,

%T 29,771,4444,8427,4444,771,29,37,1606,16366,60039,60039,16366,1606,37,

%U 46,3133,54500,384591,754758,384591,54500,3133,46,56,5789,166271,2209056

%N T(n,k)=Number of nXk 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X(k+1) binary array having a sum of two, with rows and columns of the latter in lexicographically nondecreasing order

%C Table starts

%C ..2....4......7.......11........16.........22.........29..........37.........46

%C ..4...15.....48......136.......341........771.......1606........3133.......5789

%C ..7...48....239.....1084......4444......16366......54500......166271.....470106

%C .11..136...1084.....8427.....60039.....384591....2209056....11456481...54141062

%C .16..341...4444....60039....754758....8638999...89104481...828893716.6983821643

%C .22..771..16366...384591...8638999..180409504.3428152304.58981679762

%C .29.1606..54500..2209056..89104481.3428152304

%C .37.3133.166271.11456481.828893716

%C .46.5789.470106.54141062

%H R. H. Hardin, <a href="/A227103/b227103.txt">Table of n, a(n) for n = 1..84</a>

%F Empirical for column k:

%F k=1: a(n) = (1/2)*n^2 + (1/2)*n + 1

%F k=2: [polynomial of degree 7] for n>3

%F k=3: [polynomial of degree 15] for n>5

%F k=4: [polynomial of degree 31] for n>13

%e Some solutions for n=4 k=4

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

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

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

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

%Y Column 1 is A000124

%K nonn,tabl

%O 1,1

%A _R. H. Hardin_ Jul 01 2013

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Last modified March 22 08:07 EDT 2023. Contains 361414 sequences. (Running on oeis4.)