A209521 Number of nX2 0..7 arrays with every 2X2 subblock containing exactly one value repeat, and new values 0..7 introduced in row major order

2, 6, 57, 700, 10677, 193676, 4054358, 95534880, 2472405340, 68613576496, 1999809519672, 60231323048000, 1853103730499696, 57790053276242496, 1817609007303894496, 57472115932658904064, 1823283879810883824576

Offset

1,1

Comments

Column 2 of A209527

Links

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

Formula

Empirical: a(n) = 68*a(n-1) -1410*a(n-2) +5696*a(n-3) +105944*a(n-4) -757536*a(n-5) -1207008*a(n-6) +7568640*a(n-7) +13260672*a(n-8) +4354560*a(n-9) for n>10

Example

Some solutions for n=5
..0..0....0..0....0..0....0..0....0..0....0..0....0..1....0..0....0..0....0..0
..1..2....1..2....1..2....1..2....1..2....1..2....0..2....1..2....1..2....1..2
..0..1....0..1....0..2....0..0....0..0....1..3....0..1....0..0....0..0....1..3
..2..0....0..2....3..0....3..4....1..2....0..3....3..3....1..2....2..3....0..0
..0..1....1..0....0..1....0..3....2..0....3..4....2..0....0..0....0..0....1..2

Crossrefs

Sequence in context: A209497 A209738 A209459 * A357026 A366366 A357092

Adjacent sequences: A209518 A209519 A209520 * A209522 A209523 A209524

Keyword

nonn

Author

R. H. Hardin Mar 10 2012

Status

approved