A132443 - OEIS

A132443

Number of n x n crossword puzzles with rotational symmetry and exactly one black square per row.

0, 0, 0, 2, 2, 10, 12, 120, 186

(list; graph; refs; listen; history; text; internal format)

OFFSET

3,4

COMMENTS

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

EXAMPLE

a(6) = 2 because the only two 6 X 6 crossword puzzles are (using 1's for black squares and 0's for white):

100000

000001

and

000001

100000

CROSSREFS

KEYWORD

nonn

AUTHOR

Marc Brodie (mbrodie(AT)wju.edu), Aug 21 2007

STATUS

approved