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A201723 Number of nX2 0..4 arrays with rows and columns lexicographically nondecreasing and no element equal to the number of horizontal and vertical neighbors equal to itself 1
10, 90, 631, 3567, 16493, 64018, 213013, 621757, 1626046, 3878550, 8560638, 17688966, 34541082, 64226182, 114429139, 196357695, 325924563, 525198174, 824157734, 1262790173, 1893568514, 2784353134, 4021759333, 5715036571 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 2 of A201729
LINKS
FORMULA
Empirical: a(n) = (27/560)*n^8 + (153/140)*n^7 - (1841/40)*n^6 + (29593/40)*n^5 - (474291/80)*n^4 + (1992631/120)*n^3 + (7057023/70)*n^2 - (200552137/210)*n + 2321607 for n>13
EXAMPLE
Some solutions for n=6
..0..2....0..0....2..4....0..0....0..0....0..3....0..0....2..3....0..2....0..0
..0..4....0..3....2..4....0..2....1..4....0..3....0..0....3..4....0..2....0..1
..2..4....2..0....3..2....1..3....2..2....0..3....0..4....4..0....0..3....0..2
..3..0....2..0....4..1....2..1....3..1....0..3....1..0....4..0....0..3....1..0
..3..0....3..4....4..4....3..2....3..3....0..3....4..0....4..0....2..0....2..0
..3..1....4..2....4..4....3..2....4..3....0..3....4..4....4..1....2..0....2..4
CROSSREFS
Sequence in context: A065690 A202919 A202576 * A228418 A306958 A306957
KEYWORD
nonn
AUTHOR
R. H. Hardin Dec 04 2011
STATUS
approved

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Last modified July 16 15:16 EDT 2024. Contains 374349 sequences. (Running on oeis4.)