A204601 Number of (n+2)X4 0..2 arrays with every 3X3 subblock having three strictly increasing elements in a row horizontally, vertically or nw-to-se diagonally exactly one way

29678, 144168, 741296, 4820300, 40672735, 304865717, 1982068849, 16593833004, 127399338238, 849110928402, 7077344371472, 54879638785509, 371436370197917, 3068752554068944, 23893379296037739, 163584940802316505

Offset

1,1

Comments

Column 2 of A204607

Links

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

Formula

Empirical: a(n) = 547*a(n-3) +171*a(n-4) +516*a(n-5) -55018*a(n-6) -23950*a(n-7) -111316*a(n-8) -332965*a(n-9) -876536*a(n-10) -1739333*a(n-11) -5080524*a(n-12) +403621*a(n-13) +39118183*a(n-14) +100221391*a(n-15) +150158400*a(n-16) +289571495*a(n-17) +999909003*a(n-18) +1798876517*a(n-19) +1319087584*a(n-20) +4156586902*a(n-21) +3249204289*a(n-22) +154789000*a(n-23) -450688699*a(n-24) +584511220*a(n-25) +1180063251*a(n-26) +474269436*a(n-27) -510888456*a(n-28) -433559772*a(n-29) +60300180*a(n-30) for n>33

Example

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

Crossrefs

Sequence in context: A031656 A236734 A236317 * A203502 A228544 A206203

Adjacent sequences: A204598 A204599 A204600 * A204602 A204603 A204604

Keyword

nonn

Author

R. H. Hardin Jan 17 2012

Status

approved