A205426 Number of (n+1) X 4 0..3 arrays with the number of equal 2 X 2 subblock diagonal pairs and equal antidiagonal pairs differing from each horizontal or vertical neighbor, and new values 0..3 introduced in row major order.

870, 29022, 1093244, 40007284, 1514539540, 55445403092, 2098930772556, 76841262200636, 2908798092956244, 106493580023151652, 4031150148001496108, 147588444595292151484, 5586558915888288059252, 204541422493382617854660

Offset

1,1

Comments

Column 3 of A205431.

Links

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

Formula

Empirical: a(n) = a(n-1) +1437*a(n-2) -1436*a(n-3) -73559*a(n-4) +137575*a(n-5) +1288600*a(n-6) -3105933*a(n-7) -2093681*a(n-8) +2368404*a(n-9) -65489997*a(n-10) +236894949*a(n-11) +346457313*a(n-12) -1484643168*a(n-13) -128120832*a(n-14) +2924517312*a(n-15) -2128639824*a(n-16) +1119744*a(n-17) +2855067264*a(n-18) -4073488704*a(n-19) +1273568832*a(n-20) +272097792*a(n-21) for n>22.

Example

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

Crossrefs

Sequence in context: A351878 A158669 A206172 * A035855 A317806 A031783

Adjacent sequences: A205423 A205424 A205425 * A205427 A205428 A205429

Keyword

nonn

Author

R. H. Hardin, Jan 27 2012

Status

approved