A204495 Number of (n+2)X4 0..2 arrays with every 3X3 subblock having three strictly increasing elements in a row horizontally or vertically

46458, 339311, 3418839, 42736635, 493398441, 5506995671, 66134172894, 768258278406, 8696925740970, 102969668373197, 1199508718314853, 13711731327248658, 160821909569726442, 1874375820151903499

Offset

1,1

Comments

Column 2 of A204501

Links

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

Formula

Empirical: a(n) = 9*a(n-2) +1405*a(n-3) +2925*a(n-4) +6676*a(n-5) -315819*a(n-6) -582759*a(n-7) -2320546*a(n-8) -613964*a(n-9) +16534602*a(n-10) -12987012*a(n-11) +15797781*a(n-12) -25549283*a(n-13) +5663538*a(n-14) +193388303*a(n-15) -477536947*a(n-16) -1077296979*a(n-17) -963971811*a(n-18) +1280340738*a(n-19) +4051514280*a(n-20) +5191083054*a(n-21) +4483557189*a(n-22) -1878151860*a(n-23) +13962072870*a(n-24) +10044741798*a(n-25) +25543012554*a(n-26) +1081615842*a(n-27) +23527011168*a(n-28) +2023727328*a(n-29) for n>32

Example

Some solutions for n=3
..2..2..1..2....2..1..2..1....2..2..1..2....2..1..1..2....0..1..2..1
..0..1..2..0....0..0..1..2....0..1..2..1....1..0..1..2....0..1..2..1
..1..0..1..2....0..1..2..1....0..0..1..2....0..1..2..0....0..0..1..2
..1..0..2..1....1..0..2..2....1..0..2..2....2..2..2..2....2..1..2..2
..0..1..2..2....1..0..1..2....2..1..2..1....2..0..1..2....1..2..2..0

Crossrefs

Sequence in context: A185518 A230237 A175170 * A157527 A186876 A103950

Adjacent sequences: A204492 A204493 A204494 * A204496 A204497 A204498

Keyword

nonn

Author

R. H. Hardin Jan 15 2012

Status

approved