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A219382
Number of 2 X n arrays of the minimum value of corresponding elements and their horizontal, diagonal or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and columns, 0..2 2 X n array.
1
6, 7, 14, 25, 40, 66, 103, 157, 234, 341, 486, 678, 927, 1244, 1641, 2131, 2728, 3447, 4304, 5316, 6501, 7878, 9467, 11289, 13366, 15721, 18378, 21362, 24699, 28416, 32541, 37103, 42132, 47659, 53716, 60336, 67553, 75402, 83919, 93141, 103106
OFFSET
1,1
COMMENTS
Row 2 of A219381.
LINKS
FORMULA
Empirical: a(n) = (1/24)*n^4 - (1/4)*n^3 + (35/24)*n^2 + (15/4)*n - 9 for n>5.
Conjectures from Colin Barker, Jul 26 2018: (Start)
G.f.: x*(6 - 23*x + 39*x^2 - 35*x^3 + 15*x^4 + 5*x^5 - 14*x^6 + 13*x^7 - 6*x^8 + x^9) / (1 - x)^5.
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>10.
(End)
EXAMPLE
Some solutions for n=3:
..0..0..2....1..0..1....0..0..1....0..0..1....0..0..2....0..0..0....1..1..1
..2..0..2....1..0..0....1..0..1....1..0..0....0..0..2....0..0..0....1..1..1
CROSSREFS
Cf. A219381.
Sequence in context: A058556 A332045 A022311 * A047915 A084382 A315842
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 19 2012
STATUS
approved