|
Search: id:A132446
|
|
|
| A132446 |
|
The number of n x n crossword puzzles with at most one black square per row up to horizontal/vertical symmetry. |
|
+0
4
|
| |
|
|
OFFSET
|
3,2
|
|
|
COMMENT
|
Acceptable crossword puzzles must have all words of length 3 or more, at least one word in each row and each column, and be connected.
|
|
LINKS
|
Marc Brodie, Mathematica program
|
|
EXAMPLE
|
a(5) = 3 because up to symmetry the only 5 x 5 acceptable crossword puzzles with at most one black square per row (using 1's for black squares and 0's for white) are:
00000 10000 10000
00000 00000 10000
00000 00000 00000
00000 00000 00001
00000 00001 00001
|
|
CROSSREFS
|
Cf. A130578, A132443, A132444, A132445.
Sequence in context: A135056 A132135 A131871 this_sequence A123700 A005433 A139009
Adjacent sequences: A132443 A132444 A132445 this_sequence A132447 A132448 A132449
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Marc Brodie (mbrodie(AT)wju.edu), Aug 21 2007, Aug 22 2007
|
|
|
Search completed in 0.002 seconds
|
