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A220155 Number of 3Xn arrays of the minimum value of corresponding elements and their horizontal or diagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 3Xn array 1
10, 26, 77, 254, 645, 1413, 2841, 5412, 9905, 17565, 30369, 51437, 85641, 140477, 227277, 362851, 571663, 888660, 1362889, 2062054, 3078183, 4534594, 6594369, 9470566, 13438421, 18849815, 26150305, 35899043, 48791933, 65688403, 87642197 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 3 of A220153

LINKS

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

FORMULA

Empirical: a(n) = (1/362880)*n^9 + (1/40320)*n^8 - (11/60480)*n^7 - (49/2880)*n^6 + (10837/17280)*n^5 - (30473/5760)*n^4 + (1003267/45360)*n^3 + (41353/3360)*n^2 - (594077/2520)*n + 361 for n>6

EXAMPLE

Some solutions for n=3

..2..0..0....1..0..1....1..1..1....0..0..1....1..0..0....1..0..0....0..0..0

..2..0..0....1..0..0....1..1..1....0..0..0....2..2..1....2..1..1....2..1..0

..2..0..0....2..2..1....2..1..1....1..1..0....2..2..2....2..2..2....2..1..1

CROSSREFS

Sequence in context: A072379 A005970 A192254 * A321311 A051966 A221568

Adjacent sequences:  A220152 A220153 A220154 * A220156 A220157 A220158

KEYWORD

nonn

AUTHOR

R. H. Hardin Dec 06 2012

STATUS

approved

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Last modified March 30 12:10 EDT 2020. Contains 333125 sequences. (Running on oeis4.)