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A222778
Number of n X 3 0..6 arrays with no element equal to another at a city block distance of exactly two, and new values 0..6 introduced in row major order.
1
3, 34, 969, 64752, 5227536, 436214328, 36601614264, 3073970725512, 258205634457816, 21689162608860168, 1821888109561493784, 153038579509053600072, 12855240375043076417496, 1079840187251574876131208
OFFSET
1,1
COMMENTS
Column 3 of A222779.
LINKS
FORMULA
Empirical: a(n) = 101*a(n-1) - 1470*a(n-2) + 3528*a(n-3) for n>5.
Empirical g.f.: x*(3 - 269*x + 1945*x^2 + 6279*x^3 - 7938*x^4) / ((1 - 3*x)*(1 - 14*x)*(1 - 84*x)). - Colin Barker, Aug 16 2018
EXAMPLE
Some solutions for n=3:
..0..1..2....0..1..2....0..1..2....0..1..1....0..1..2....0..1..2....0..1..2
..3..4..2....3..3..0....3..3..4....0..2..3....3..1..4....2..1..3....0..3..4
..2..5..0....4..2..0....1..0..4....1..4..0....5..0..4....4..5..3....1..2..4
CROSSREFS
Cf. A222779.
Sequence in context: A222869 A069718 A077144 * A101633 A250093 A054783
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 05 2013
STATUS
approved