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A202910 Number of nX2 0..7 arrays with every nonzero element less than or equal to some horizontal or vertical neighbor 1
8, 680, 31984, 1194376, 44344428, 1707628408, 66085464308, 2542636404496, 97688506009926, 3756426746800752, 144493565678435826, 5557405757222316520, 213730533301348703138, 8219904362839412920344, 316134938792029283711026 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A202916

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 36*a(n-1) -238*a(n-2) +11172*a(n-3) +34719*a(n-4) +951582*a(n-5) +3347114*a(n-6) +29399988*a(n-7) +80056473*a(n-8) +374118253*a(n-9) +709288548*a(n-10) +1969872705*a(n-11) +2317452024*a(n-12) +3743198992*a(n-13) +2076708096*a(n-14) +1625702400*a(n-15)

EXAMPLE

Some solutions for n=4

..7..6....3..3....4..2....4..5....2..6....7..5....3..0....2..3....2..0....1..5

..7..5....1..3....4..1....0..6....1..6....7..4....3..0....7..3....3..1....7..5

..5..6....5..4....3..1....4..6....7..6....1..4....2..2....7..2....3..2....7..1

..1..6....5..0....4..4....4..6....7..0....1..0....3..3....3..2....0..0....2..0

CROSSREFS

Sequence in context: A278857 A334088 A343191 * A332168 A168130 A270871

Adjacent sequences:  A202907 A202908 A202909 * A202911 A202912 A202913

KEYWORD

nonn

AUTHOR

R. H. Hardin Dec 26 2011

STATUS

approved

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Last modified October 4 18:23 EDT 2022. Contains 357239 sequences. (Running on oeis4.)