The On-Line Encyclopedia of Integer Sequences (OEIS)

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A181239

Number of n X 4 binary matrices with no 2 X 2 circuit having pattern 0101 in any orientation.
(history; published version)

#6 by Alois P. Heinz at Mon Mar 26 14:25:25 EDT 2018

STATUS

proposed

approved

#5 by Colin Barker at Mon Mar 26 13:58:57 EDT 2018

STATUS

editing

proposed

#4 by Colin Barker at Mon Mar 26 13:58:42 EDT 2018

NAME

Number of nX4 n X 4 binary matrices with no 2X2 2 X 2 circuit having pattern 0101 in any orientation.

COMMENTS

Column 4 of A181245.

FORMULA

Empirical: a(n) = 10*a(n-1) + 20*a(n-2) - 21*a(n-3) - 30*a(n-4) + 8*a(n-5).

Empirical g.f.: 2*x*(8 + 9*x - 17*x^2 - 13*x^3 + 4*x^4) / (1 - 10*x - 20*x^2 + 21*x^3 + 30*x^4 - 8*x^5). - Colin Barker, Mar 26 2018

CROSSREFS

Cf. A181245.

AUTHOR

R. H. Hardin , Oct 10 2010

STATUS

approved

editing

#3 by Russ Cox at Sat Mar 31 12:35:49 EDT 2012

AUTHOR

_R. H. Hardin (rhhardin(AT)att.net) _ Oct 10 2010

Discussion

Sat Mar 31

12:35

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

#2 by N. J. A. Sloane at Thu Nov 11 07:34:06 EST 2010

LINKS

R. H. Hardin, <a href="/A181239/b181239.txt">Table of n, a(n) for n=1..200</a>

KEYWORD

nonn,new

nonn

#1 by N. J. A. Sloane at Wed Oct 20 03:00:00 EDT 2010

NAME

Number of nX4 binary matrices with no 2X2 circuit having pattern 0101 in any orientation

DATA

16, 178, 2066, 23858, 275690, 3185462, 36806846, 425288998, 4914052362, 56780001474, 656071271338, 7580653428086, 87591560417790, 1012087088416198, 11694280472399626, 135122952690874754, 1561294205914890890

OFFSET

1,1

COMMENTS

Column 4 of A181245

LINKS

R. H. Hardin, <a href="b181239.txt">Table of n, a(n) for n=1..200</a>

FORMULA

Empirical: a(n)=10*a(n-1)+20*a(n-2)-21*a(n-3)-30*a(n-4)+8*a(n-5)

KEYWORD

nonn,new

AUTHOR

R. H. Hardin (rhhardin(AT)att.net) Oct 10 2010

STATUS

approved