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A227165 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 one or less, with rows and columns of the latter in lexicographically nondecreasing order 6

%I #4 Jul 03 2013 06:27:08

%S 2,3,3,4,8,4,5,18,18,5,6,36,62,36,6,7,66,193,193,66,7,8,113,558,944,

%T 558,113,8,9,183,1507,4528,4528,1507,183,9,10,283,3828,20336,37012,

%U 20336,3828,283,10,11,421,9149,85018,283430,283430,85018,9149,421,11,12,606

%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 one or less, with rows and columns of the latter in lexicographically nondecreasing order

%C Table starts

%C ..2...3.....4.......5........6..........7............8............9

%C ..3...8....18......36.......66........113..........183..........283

%C ..4..18....62.....193......558.......1507.........3828.........9149

%C ..5..36...193.....944.....4528......20336........85018.......330949

%C ..6..66...558....4528....37012.....283430......2010569.....13174529

%C ..7.113..1507...20336...283430....3754497.....46389565....529521521

%C ..8.183..3828...85018..2010569...46389565...1009485843..20376855291

%C ..9.283..9149..330949.13174529..529521521..20376855291.732609096798

%C .10.421.20609.1200425.79606861.5548518625.377546087348

%H R. H. Hardin, <a href="/A227165/b227165.txt">Table of n, a(n) for n = 1..127</a>

%F Empirical for column k:

%F k=1: a(n) = n + 1

%F k=2: a(n) = (1/24)*n^4 + (1/12)*n^3 + (23/24)*n^2 + (11/12)*n + 1

%F k=3: [polynomial of degree 9] for n>3

%F k=4: [polynomial of degree 19] for n>8

%F k=5: [polynomial of degree 39] for n>19

%e Some solutions for n=4 k=4

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

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

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

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

%K nonn,tabl

%O 1,1

%A _R. H. Hardin_ Jul 03 2013

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Last modified May 3 18:51 EDT 2024. Contains 372222 sequences. (Running on oeis4.)