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Revision History for A250609

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Number of (n+1) X (6+1) 0..1 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)-x(i-1,j) in the j direction.
(history; published version)
#7 by Susanna Cuyler at Thu Nov 15 08:38:48 EST 2018
STATUS

proposed

approved

#6 by Colin Barker at Thu Nov 15 08:37:21 EST 2018
STATUS

editing

proposed

#5 by Colin Barker at Thu Nov 15 08:36:57 EST 2018
NAME

Number of (n+1) X (6+1) 0..1 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)-x(i-1,j) in the j direction.

COMMENTS

Column 6 of A250611

FORMULA

Empirical: a(n) = 5*a(n-1) - 9*a(n-2) + 7*a(n-3) - 2*a(n-4).

Empirical: a(n) = 196*2^(n-1) + 99*n^2 + 177*n + 30.

Empirical g.f.: 2*x*(251 - 669*x + 447*x^2 - 128*x^3) / ((1 - x)^3*(1 - 2*x)). - Colin Barker, Nov 15 2018

EXAMPLE

Some solutions for n=6:

CROSSREFS

Column 6 of A250611.

STATUS

approved

editing

#4 by R. H. Hardin at Wed Nov 26 09:26:54 EST 2014
STATUS

editing

approved

#3 by R. H. Hardin at Wed Nov 26 09:26:44 EST 2014
LINKS

R. H. Hardin, <a href="/A250609/b250609.txt">Table of n, a(n) for n = 1..210</a>

#2 by R. H. Hardin at Wed Nov 26 09:25:56 EST 2014
NAME

allocated for R. H. Hardin

Number of (n+1)X(6+1) 0..1 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)-x(i-1,j) in the j direction

DATA

502, 1172, 2236, 3890, 6526, 10928, 18664, 32870, 59818, 112052, 214660, 417818, 821878, 1627544, 3236224, 6450734, 12876706, 25725404, 51419356, 102803618, 205568302, 411093632, 822140056, 1644228470, 3288400666, 6576740228

OFFSET

1,1

COMMENTS

Column 6 of A250611

FORMULA

Empirical: a(n) = 5*a(n-1) -9*a(n-2) +7*a(n-3) -2*a(n-4)

Empirical: a(n) = 196*2^(n-1) +99*n^2 +177*n +30

EXAMPLE

Some solutions for n=6

..1..0..1..1..0..1..0....1..1..1..1..1..0..0....0..0..0..0..0..0..0

..1..0..1..1..0..1..1....0..0..0..0..1..0..0....1..1..1..1..1..1..1

..0..0..1..1..0..1..1....0..0..0..0..1..0..0....0..0..0..0..0..0..0

..0..0..1..1..0..1..1....0..0..0..0..1..0..0....1..1..1..1..1..1..1

..0..0..1..1..0..1..1....0..0..0..0..1..0..1....1..1..1..1..1..1..1

..0..0..1..1..0..1..1....0..0..0..0..1..0..1....0..0..0..0..0..0..0

..0..0..1..1..0..1..1....0..0..0..0..1..0..1....0..0..0..1..1..1..1

KEYWORD

allocated

nonn

AUTHOR

R. H. Hardin, Nov 26 2014

STATUS

approved

editing

#1 by R. H. Hardin at Wed Nov 26 09:14:25 EST 2014
NAME

allocated for R. H. Hardin

KEYWORD

allocated

STATUS

approved