A234764 Number of (n+1)X(3+1) 0..3 arrays with 2X2 edge jumps all no more than +1 in one of the clockwise or counterclockwise directions but not both

916, 9404, 71280, 760072, 6340684, 65760368, 570633100, 5760421980, 51229946356, 506912579200, 4585445351168, 44729758557596, 409491022800436, 3954330139702396, 36508823443666324, 350044836839297844

Offset

1,1

Comments

Column 3 of A234769

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +137*a(n-2) -284*a(n-3) -6386*a(n-4) +9604*a(n-5) +145993*a(n-6) -160399*a(n-7) -1876827*a(n-8) +1488326*a(n-9) +14432970*a(n-10) -8040903*a(n-11) -68366990*a(n-12) +25519880*a(n-13) +201876831*a(n-14) -47552365*a(n-15) -371183764*a(n-16) +52834992*a(n-17) +418743519*a(n-18) -37830792*a(n-19) -280238238*a(n-20) +20541150*a(n-21) +104060106*a(n-22) -8730936*a(n-23) -18816300*a(n-24) +2167560*a(n-25) +1263600*a(n-26) -194400*a(n-27)

Example

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

Crossrefs

Sequence in context: A252427 A074887 A234993 * A282592 A029897 A221387

Adjacent sequences: A234761 A234762 A234763 * A234765 A234766 A234767

Keyword

nonn

Author

R. H. Hardin, Dec 30 2013

Status

approved