A234771 Number of (n+1)X(2+1) 0..4 arrays with 2X2 edge jumps all no more than +1 in one of the clockwise or counterclockwise directions but not both

454, 3980, 28840, 247394, 1912554, 16146124, 127371542, 1063565190, 8483787204, 70296753566, 564722797390, 4654352266800, 37565456132170, 308475061482182, 2497492686007104, 20457411426855534, 165975465953392246

Offset

1,1

Comments

Column 2 of A234777

Links

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

Formula

Empirical: a(n) = 9*a(n-1) +60*a(n-2) -657*a(n-3) -510*a(n-4) +14451*a(n-5) -9878*a(n-6) -143349*a(n-7) +195967*a(n-8) +711924*a(n-9) -1328829*a(n-10) -1738223*a(n-11) +4362370*a(n-12) +1713737*a(n-13) -7406892*a(n-14) +154943*a(n-15) +6781020*a(n-16) -1542017*a(n-17) -3326149*a(n-18) +1109694*a(n-19) +807890*a(n-20) -310656*a(n-21) -75048*a(n-22) +30144*a(n-23)

Example

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

Crossrefs

Sequence in context: A365619 A259058 A213532 * A297658 A219006 A092267

Adjacent sequences: A234768 A234769 A234770 * A234772 A234773 A234774

Keyword

nonn

Author

R. H. Hardin, Dec 30 2013

Status

approved