A205739 Number of 4X(n+1) 0..2 arrays with every 2 X 2 subblock having the same number of clockwise edge increases as its horizontal neighbors and no 2 X 2 subblock having the same number of counterclockwise edge increases as its vertical neighbors.

1683, 3318, 14715, 80088, 450339, 2565900, 14781282, 85852548, 502097979, 2953275825, 17454550770, 103577971653, 616733949822, 3682641041940, 22041854965854, 132187997823285, 794047508972499, 4776288839441496

Offset

1,1

Comments

Row 3 of A205736.

Links

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

Formula

Empirical: a(n) = 23*a(n-1) -207*a(n-2) +867*a(n-3) -1178*a(n-4) -3567*a(n-5) +15272*a(n-6) -12652*a(n-7) -30210*a(n-8) +69591*a(n-9) -24010*a(n-10) -68468*a(n-11) +85661*a(n-12) -25742*a(n-13) -16279*a(n-14) +13561*a(n-15) -2008*a(n-16) -1025*a(n-17) +416*a(n-18) -44*a(n-19) for n>23.

Example

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

Crossrefs

Sequence in context: A035766 A107562 A031539 * A031719 A206671 A205515

Adjacent sequences: A205736 A205737 A205738 * A205740 A205741 A205742

Keyword

nonn

Author

R. H. Hardin, Jan 30 2012

Status

approved