A194497 - OEIS

A194497

Number of ways to arrange 7 nonattacking queens on the lower triangle of an n X n board.

0, 0, 0, 0, 0, 0, 0, 0, 0, 10, 1210, 27198, 322782, 2564988, 15372702, 74615814, 306900410, 1105651074, 3569169990, 10512880400, 28628691842, 72880455042, 174895586328, 398556484840, 867314768878, 1811576604968, 3646385889888

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

OFFSET

1,10

COMMENTS

Column 7 of A194498.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..28

EXAMPLE

Some solutions for 10 X 10:

0 0 0

0 0 0 0 0 0

0 0 0 0 0 0 0 0 0

0 1 0 0 0 1 0 0 0 0 0 1

0 0 0 1 0 0 0 0 1 0 1 0 0 0 0

1 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 0

0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 1 0

0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0

0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0

0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0

CROSSREFS

Sequence in context: A233252 A249849 A027879 * A287226 A015108 A070065

Adjacent sequences: A194494 A194495 A194496 * A194498 A194499 A194500

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 26 2011

STATUS

approved