login
A198663
Number of nX2 0..4 arrays with values 0..4 introduced in row major order and each element equal to one or two horizontal and vertical neighbors
1
1, 3, 13, 65, 401, 2798, 21243, 170477, 1414186, 11959573, 102256003, 879709138, 7594221063, 65683697809, 568711886538, 4926993076641, 42698505718759, 370102007685234, 3208288130917763, 27813084430989669, 241122723310051914
OFFSET
1,2
COMMENTS
Column 2 of A198669
LINKS
FORMULA
Empirical: a(n) = 12*a(n-1) -18*a(n-2) -96*a(n-3) -43*a(n-4) +384*a(n-5) +1030*a(n-6) +276*a(n-7) -1609*a(n-8) -3144*a(n-9) -1688*a(n-10) +1080*a(n-11) +1536*a(n-12) +768*a(n-13) -512*a(n-14) for n>16
EXAMPLE
Some solutions with all values 0 to 4 for n=6
..0..0....0..1....0..1....0..0....0..0....0..0....0..0....0..1....0..0....0..1
..1..2....0..1....0..1....1..1....1..1....1..2....1..1....0..1....1..0....0..1
..1..2....1..1....2..1....2..3....2..2....1..2....2..2....2..3....1..2....2..3
..3..3....2..2....2..2....2..3....3..3....3..0....3..4....2..3....3..2....2..3
..1..1....3..3....3..4....1..4....3..3....3..0....3..4....3..4....3..3....4..2
..4..4....4..4....3..4....1..4....4..4....4..4....4..4....3..4....4..4....4..2
CROSSREFS
Sequence in context: A080227 A199143 A002468 * A156181 A260783 A373932
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 28 2011
STATUS
approved