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A219293 Number of n X 2 arrays of the minimum value of corresponding elements and their horizontal, vertical or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and columns, 0..2 n X 2 array. 1
3, 7, 17, 35, 62, 103, 165, 257, 390, 577, 833, 1175, 1622, 2195, 2917, 3813, 4910, 6237, 7825, 9707, 11918, 14495, 17477, 20905, 24822, 29273, 34305, 39967, 46310, 53387, 61253, 69965, 79582, 90165, 101777, 114483, 128350, 143447, 159845, 177617 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A219299.

LINKS

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

FORMULA

Empirical: a(n) = (1/12)*n^4 - (2/3)*n^3 + (53/12)*n^2 - (17/6)*n - 3 for n > 2.

Conjectures from Colin Barker, Jul 25 2018: (Start)

G.f.: x*(3 - 8*x + 12*x^2 - 10*x^3 + 2*x^4 + 5*x^5 - 2*x^6) / (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 > 7.

(End)

EXAMPLE

Some solutions for n=3:

  2 2   1 0   1 1   0 0   1 1   0 0   0 0   0 0   0 0   0 0

  2 2   0 0   1 0   0 1   1 1   0 0   0 0   0 0   0 0   0 0

  2 2   0 0   0 0   1 1   1 2   2 2   0 2   1 2   0 0   0 1

CROSSREFS

Cf. A219299.

Sequence in context: A295089 A168582 A192958 * A178521 A034482 A114100

Adjacent sequences:  A219290 A219291 A219292 * A219294 A219295 A219296

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 17 2012

STATUS

approved

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Last modified July 29 09:41 EDT 2021. Contains 346344 sequences. (Running on oeis4.)