|
Search: id:A034182
|
|
|
| A034182 |
|
Not necessarily symmetric n x 2 crossword puzzle grids. |
|
+0
15
|
|
| 1, 5, 15, 39, 97, 237, 575, 1391, 3361, 8117, 19599, 47319, 114241, 275805, 665855, 1607519, 3880897, 9369317, 22619535, 54608391, 131836321, 318281037, 768398399, 1855077839, 4478554081, 10812186005, 26102926095, 63018038199
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
COMMENT
|
n X 2 binary arrays with a path of adjacent 1's and no path of adjacent 0's from top row to bottom row. - Ron Hardin (rhhardin(AT)att.net), Mar 21 2002
|
|
FORMULA
|
a(n) = 2a(n-1)+a(n-2)+4
a(n)=-2+(3/2)*[1+sqrt(2)]^(n-1)-sqrt(2)*[1-sqrt(2)]^(n-1)+(3/2)*[1-sqrt(2)]^(n-1)+[1+sqrt(2)]^(n-1) *sqrt(2), with n>=1 - Paolo P. Lava (ppl(AT)spl.at), Jun 10 2008
|
|
CROSSREFS
|
Sequence in context: A062487 A084447 A099035 this_sequence A132985 A022570 A152881
Adjacent sequences: A034179 A034180 A034181 this_sequence A034183 A034184 A034185
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Erich Friedman (erich.friedman(AT)stetson.edu)
|
|
|
Search completed in 0.002 seconds
|
