A251108 Number of (n+1)X(3+1) 0..2 arrays with no 2X2 subblock having the maximum of its diagonal elements greater than the absolute difference of its antidiagonal elements

526, 3616, 19131, 99147, 549944, 3097574, 17154384, 94541640, 523362695, 2902098174, 16074820995, 88991683894, 492794584784, 2729305867906, 15115136455485, 83704974778717, 463549806671218, 2567128453854706

Offset

1,1

Comments

Column 3 of A251113

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 21*a(n-1) -208*a(n-2) +1340*a(n-3) -6378*a(n-4) +23759*a(n-5) -71215*a(n-6) +174232*a(n-7) -350668*a(n-8) +582938*a(n-9) -801786*a(n-10) +912272*a(n-11) -856248*a(n-12) +658631*a(n-13) -408814*a(n-14) +196251*a(n-15) -63460*a(n-16) +5494*a(n-17) +6902*a(n-18) -3702*a(n-19) +790*a(n-20) -368*a(n-21) +453*a(n-22) -295*a(n-23) +89*a(n-24) -7*a(n-25) -a(n-26) for n>27

Example

Some solutions for n=4
..0..0..0..1....0..0..1..2....1..1..1..2....1..0..2..2....0..0..1..2
..2..0..0..0....0..0..1..1....0..0..0..2....1..1..0..1....0..0..1..0
..2..2..2..0....0..0..0..0....0..0..0..2....0..1..0..0....0..0..1..1
..0..0..2..0....2..2..0..0....1..1..0..2....0..1..1..0....1..1..0..0
..1..0..2..1....0..2..0..0....0..1..0..2....2..0..1..0....2..1..0..0

Crossrefs

Sequence in context: A294984 A020379 A251022 * A204472 A264804 A093226

Adjacent sequences: A251105 A251106 A251107 * A251109 A251110 A251111

Keyword

nonn

Author

R. H. Hardin, Nov 30 2014

Status

approved