|
|
A058482
|
|
Number of 3 X n binary matrices with no zero rows or columns.
|
|
3
|
|
|
1, 25, 265, 2161, 16081, 115465, 816985, 5745121, 40294561, 282298105, 1976795305, 13839692881, 96884227441, 678208723945, 4747518463225, 33232801429441, 232630126566721, 1628412435648985, 11398891698588745, 79792255837258801, 558545832702224401
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
LINKS
|
|
|
FORMULA
|
Number of m X n binary matrices with no zero rows or columns is Sum_{j=0..m}(-1)^j*C(m, j)*(2^(m-j)-1)^n.
a(n) = 7^n-3*3^n+3.
a(n) = 11*a(n-1)-31*a(n-2)+21*a(n-3). G.f.: -x*(21*x^2+14*x+1) / ((x-1)*(3*x-1)*(7*x-1)). - Colin Barker, Jul 10 2013
|
|
MATHEMATICA
|
LinearRecurrence[{11, -31, 21}, {1, 25, 265}, 30] (* Harvey P. Dale, Aug 15 2014 *)
|
|
PROG
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
easy,nonn,nice
|
|
AUTHOR
|
|
|
EXTENSIONS
|
More terms from Larry Reeves (larryr(AT)acm.org), Dec 04 2000
|
|
STATUS
|
approved
|
|
|
|