The On-Line Encyclopedia of Integer Sequences (OEIS)

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A183683

Number of (n+1) X 5 binary arrays with every 2 X 2 subblock nonsingular.
(history; published version)

#9 by Joerg Arndt at Wed Apr 04 12:04:20 EDT 2018

STATUS

reviewed

approved

#8 by Michel Marcus at Wed Apr 04 06:45:37 EDT 2018

STATUS

proposed

reviewed

#7 by Colin Barker at Wed Apr 04 04:58:16 EDT 2018

STATUS

editing

proposed

#6 by Colin Barker at Wed Apr 04 04:57:51 EDT 2018

NAME

Number of (n+1)X5 X 5 binary arrays with every 2X2 2 X 2 subblock nonsingular.

COMMENTS

Column 4 of A183688.

FORMULA

Empirical: a(n) = 13*a(n-2) + 16*a(n-3).

Empirical g.f.: 16*x*(3 + 13*x + 13*x^2) / (1 - 13*x^2 - 16*x^3). - Colin Barker, Apr 04 2018

EXAMPLE

Some solutions for 3X53 X 5:

CROSSREFS

Cf. A183688.

AUTHOR

R. H. Hardin , Jan 06 2011

STATUS

approved

editing

#5 by Russ Cox at Sat Mar 31 12:35:53 EDT 2012

AUTHOR

_R. H. Hardin (rhhardin(AT)att.net) _ Jan 06 2011

Discussion

Sat Mar 31

12:35

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

#4 by Ron Hardin at Thu Jan 06 09:37:58 EST 2011

STATUS

proposed

approved

#3 by Ron Hardin at Thu Jan 06 09:37:48 EST 2011

LINKS

R. H. Hardin, <a href="/A183683/b183683.txt">Table of n, a(n) for n = 1..200</a>

#2 by Ron Hardin at Thu Jan 06 09:37:16 EST 2011

NAME

allocated for Ron HardinNumber of (n+1)X5 binary arrays with every 2X2 subblock nonsingular

DATA

48, 208, 832, 3472, 14144, 58448, 239424, 986128, 4047680, 16650448, 68397888, 281218704, 1155579712, 4750209360, 19522035520, 80241997072, 329789811520, 1355498530256, 5571139502912, 22898117877648, 94112790021952

OFFSET

1,1

COMMENTS

Column 4 of A183688

FORMULA

Empirical: a(n)=13*a(n-2)+16*a(n-3)

EXAMPLE

Some solutions for 3X5

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

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

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

KEYWORD

allocated

nonn

AUTHOR

R. H. Hardin (rhhardin(AT)att.net) Jan 06 2011

STATUS

approved

proposed

#1 by Ron Hardin at Thu Jan 06 09:30:35 EST 2011

NAME

allocated for Ron Hardin

KEYWORD

allocated

STATUS

approved