A232297 Number of 3Xn 0..2 arrays with every 0 next to a 1 and every 1 next to a 2 horizontally or antidiagonally

1, 73, 1313, 20563, 336079, 5546705, 91293443, 1501960031, 24713799985, 406656992827, 6691352475451, 110103034876825, 1811693873275549, 29810574840844381, 490519050740934291, 8071261298331724901

Offset

1,2

Comments

Row 3 of A232295

Links

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

Formula

Empirical: a(n) = 17*a(n-1) -26*a(n-2) +300*a(n-3) -357*a(n-4) +649*a(n-5) -2086*a(n-6) -7704*a(n-7) +4629*a(n-8) -5443*a(n-9) +93145*a(n-10) +85905*a(n-11) -157839*a(n-12) -729737*a(n-13) -915875*a(n-14) +3209385*a(n-15) +2752272*a(n-16) -5724052*a(n-17) -1434321*a(n-18) +3054997*a(n-19) -1305232*a(n-20) +1344058*a(n-21) +934144*a(n-22) -1112478*a(n-23) +130446*a(n-24) -347652*a(n-25) -83617*a(n-26) +131475*a(n-27) -44419*a(n-28) +74435*a(n-29) -8240*a(n-30) +8400*a(n-31)

Example

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

Crossrefs

Sequence in context: A346642 A008400 A090685 * A008392 A221479 A253263

Adjacent sequences: A232294 A232295 A232296 * A232298 A232299 A232300

Keyword

nonn

Author

R. H. Hardin, Nov 22 2013

Status

approved