OFFSET
0,2
EXAMPLE
a(2)=9 because we can reach (2,2) in the following ways:
(1,0),(1,0),(0,1),(0,1)
(1,0),(1,0),(0,2)
(2,0),(0,1),(0,1)
(2,0),(0,2)
(1,0),(1,1),(0,1)
(1,0),(0,1),(1,1)
(1,1),(1,0),(0,1)
(1,1),(0,1),(1,0)
(1,1)(1,1)
CROSSREFS
KEYWORD
nonn
AUTHOR
Eric Werley, Dec 05 2010
STATUS
approved