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A185819 1/5 the number of nX3 0..4 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors 1
1, 76, 1584, 49036, 1266624, 35446376, 956312244, 26231137608, 714107480512, 19507209473948, 532049001583280, 14521612514267224, 396222067735245796, 10812492512879834968, 295042237941175359056, 8051107927651445871340 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Column 3 of A185825
LINKS
FORMULA
Empirical: a(n)=17*a(n-1)+327*a(n-2)-1020*a(n-3)-6773*a(n-4)+2794*a(n-5)+32525*a(n-6)+131655*a(n-7)-337771*a(n-8)+33788*a(n-9)+517885*a(n-10)-1145646*a(n-11)-5007180*a(n-12)+7715688*a(n-13)+39324336*a(n-14)-82942336*a(n-15)-35554304*a(n-16)+265939200*a(n-17)+170422272*a(n-18)-172261376*a(n-19)-774750208*a(n-20)-958660608*a(n-21)-1396703232*a(n-22)-1811939328*a(n-23)
EXAMPLE
Some solutions for 4X3 with a(1,1)=0
..0..1..1....0..3..3....0..3..1....0..0..1....0..2..3....0..0..2....0..0..2
..0..1..0....0..4..3....0..3..1....0..1..1....0..2..3....0..2..2....4..4..2
..0..0..0....4..4..2....0..2..2....2..1..3....0..2..4....4..4..4....1..4..4
..1..1..1....4..2..2....1..1..2....2..1..3....0..2..4....1..1..1....1..1..1
CROSSREFS
Sequence in context: A163710 A293310 A061618 * A270960 A060190 A156399
KEYWORD
nonn
AUTHOR
R. H. Hardin Feb 05 2011
STATUS
approved

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Last modified May 26 00:51 EDT 2024. Contains 372806 sequences. (Running on oeis4.)