|
Search: id:A069361
|
|
|
| A069361 |
|
Number of 3 X n binary arrays with a path of adjacent 1's from top row to bottom row. |
|
+0
92
|
|
| 1, 17, 197, 1985, 18621, 167337, 1461797, 12519345, 105683341, 882516857, 7308428597, 60131384705, 492202181661, 4012347269577, 32599584662597, 264152863210065, 2135714594033581, 17236446198921497, 138901692341235797
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
FORMULA
|
G.f.: x*(1+2*x)/(1-8*x)/(2*x^2-7*x+1). - Vladeta Jovovic (vladeta(AT)Eunet.yu), Jul 02 2003
Recurrence: a(n)=15*a(n-1)-58*a(n-2)+16*a(n-3), where a(1)=1, a(2)=17, a(3)=197; formula a(n)=8^n+1/sqrt(41)*4^(n+1)*((7+sqrt(41))^(-(n+1))-(7-sqrt(41))^(-(n+1))) - Maksym Voznyy (voznyy(AT)mail.ru), Jul 25 2008
|
|
CROSSREFS
|
Cf. 1 X n A000225, 2 X n A005061, n X 2 A001333, vertical path of 1 A069361-A069395, vertical paths of 0+1 A069396-A069416, vertical path of 1 not 0 A069417-A069428, no vertical paths A069429-A069447, no horizontal or vertical paths A069448-A069452.
Sequence in context: A019316 A018250 A021184 this_sequence A130817 A055432 A021379
Adjacent sequences: A069358 A069359 A069360 this_sequence A069362 A069363 A069364
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Ron Hardin (rhhardin(AT)att.net), Mar 22 2002.
|
|
|
Search completed in 0.002 seconds
|
