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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 1
454, 3980, 28840, 247394, 1912554, 16146124, 127371542, 1063565190, 8483787204, 70296753566, 564722797390, 4654352266800, 37565456132170, 308475061482182, 2497492686007104, 20457411426855534, 165975465953392246 (list; graph; refs; listen; history; text; internal format)
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: A076547 A259058 A213532 * A297658 A219006 A092267

Adjacent sequences:  A234768 A234769 A234770 * A234772 A234773 A234774

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 30 2013

STATUS

approved

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Last modified September 22 03:20 EDT 2021. Contains 347605 sequences. (Running on oeis4.)