The On-Line Encyclopedia of Integer Sequences (OEIS)

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A185829

Half the number of nX3 binary arrays with every element equal to exactly one or two of its horizontal and vertical neighbors
(history; published version)

#7 by Russ Cox at Sat Mar 31 12:36:03 EDT 2012

AUTHOR

_R. H. Hardin (rhhardin(AT)att.net) _ Feb 05 2011

Discussion

Sat Mar 31

12:36

OEIS Server: https://oeis.org/edit/global/875

#6 by Ron Hardin at Sun Feb 06 06:10:46 EST 2011

STATUS

proposed

approved

#5 by Ron Hardin at Sun Feb 06 06:10:42 EST 2011

NAME

Half the number of nX3 binary arrays with with every element equal to exactly one or two of its horizontal and vertical neighbors

STATUS

approved

proposed

#4 by Ron Hardin at Sat Feb 05 07:59:12 EST 2011

STATUS

proposed

approved

#3 by Ron Hardin at Sat Feb 05 07:59:05 EST 2011

LINKS

R. H. Hardin, <a href="/A185829/b185829.txt">Table of n, a(n) for n = 1..200</a>

#2 by Ron Hardin at Sat Feb 05 07:58:41 EST 2011

NAME

allocated for Ron HardinHalf the number of nX3 binary arrays with with every element equal to exactly one or two of its horizontal and vertical neighbors

DATA

1, 10, 30, 118, 393, 1430, 5004, 17877, 63181, 224324, 794939, 2819380, 9995857, 35445025, 125677385, 445630567, 1580102608, 5602722348, 19866041906, 70440800557, 249768066156, 885624613914, 3140236676877, 11134612682393

OFFSET

1,2

COMMENTS

Column 3 of A185835

FORMULA

Empirical: a(n)=2*a(n-1)+6*a(n-2)-a(n-3)-3*a(n-4)+4*a(n-5)-4*a(n-6)-32*a(n-7)-9*a(n-8)-4*a(n-9)-19*a(n-10)+17*a(n-11)+3*a(n-12)+a(n-13)-a(n-14)

EXAMPLE

Some solutions for 4X3 with a(1,1)=0

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

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

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

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

KEYWORD

allocated

nonn

AUTHOR

R. H. Hardin (rhhardin(AT)att.net) Feb 05 2011

STATUS

approved

proposed

#1 by Ron Hardin at Sat Feb 05 07:55:20 EST 2011

NAME

allocated for Ron Hardin

KEYWORD

allocated

STATUS

approved