A230271 Number of nX4 0..2 arrays x(i,j) with each element horizontally or vertically next to at least one element with value (x(i,j)+1) mod 3, and upper left element zero

0, 8, 258, 5734, 115630, 2348840, 47524048, 960953664, 19434635008, 393014342648, 7947832428594, 160726163583236, 3250310723233232, 65729917778160590, 1329233592071759468, 26880635176607700958, 543597868086408426752

Offset

1,2

Comments

Column 4 of A230275

Links

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

Formula

Empirical: a(n) = 32*a(n-1) -253*a(n-2) -23*a(n-3) +7788*a(n-4) -23108*a(n-5) -68995*a(n-6) +486597*a(n-7) -945385*a(n-8) +1878820*a(n-9) -4005328*a(n-10) -30758253*a(n-11) +205234979*a(n-12) -495083591*a(n-13) +715035720*a(n-14) -1028797009*a(n-15) +1669240904*a(n-16) -2143236961*a(n-17) +1938990337*a(n-18) -964345338*a(n-19) -398834793*a(n-20) +634628137*a(n-21) +100251914*a(n-22) +609976551*a(n-23) -900597318*a(n-24) -118049796*a(n-25) -55188026*a(n-26) +299145317*a(n-27) +64433942*a(n-28) -112668037*a(n-29) +85226423*a(n-30) -117488386*a(n-31) +20732900*a(n-32) +39375976*a(n-33) -14555736*a(n-34)

Example

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

Crossrefs

Sequence in context: A341479 A041487 A034988 * A221778 A172127 A230611

Adjacent sequences: A230268 A230269 A230270 * A230272 A230273 A230274

Keyword

nonn

Author

R. H. Hardin, Oct 14 2013

Status

approved