|
|
A050204
|
|
a(n) is the number of n X n matrices of 0's, 1's and -1's in which the entries in each row or column sum to 1.
|
|
4
|
|
|
1, 2, 21, 1344, 628080, 2030271480, 49846153939785, 9350902053107858880, 13807842729396124460629536, 162526525004284727135887319788800, 15464071313054035722739424623204673044920, 12011244510939290610945342901003078567310643860160
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
LINKS
|
|
|
CROSSREFS
|
Cf. A229165 (entries in each row or column sum to 1 and there are no adjacent -1's or 1's in any row or column).
Cf. A172645 (case row and column sums are zero).
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
Definition corrected by Murphy Waggoner and R. H. Hardin, Sep 24 2013
|
|
STATUS
|
approved
|
|
|
|