A233619 Number of (1+2)X(n+2) 0..2 arrays with no increasing sequence of length 3 horizontally or diagonally downwards

17064, 395955, 9120456, 209902869, 4828862487, 111082137228, 2555252447715, 58778922784197, 1352100211331256, 31102552274705091, 715456354940060904, 16457742231238562607, 378579736397149596549, 8708522388417534975621

Offset

1,1

Comments

Row 1 of A233618

Links

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

Formula

Empirical: a(n) = 29*a(n-1) -84*a(n-2) -1570*a(n-3) +6618*a(n-4) +28026*a(n-5) -136815*a(n-6) -145173*a(n-7) +1005714*a(n-8) -486446*a(n-9) -1842056*a(n-10) +1805556*a(n-11) +1069186*a(n-12) -1763040*a(n-13) +27675*a(n-14) +626313*a(n-15) -148782*a(n-16) -66294*a(n-17) +19454*a(n-18) +2708*a(n-19) -849*a(n-20) -37*a(n-21) +12*a(n-22)

Example

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

Crossrefs

Sequence in context: A252129 A252472 A233618 * A233611 A233610 A361349

Adjacent sequences: A233616 A233617 A233618 * A233620 A233621 A233622

Keyword

nonn

Author

R. H. Hardin, Dec 14 2013

Status

approved