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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. A005130 (Robbins numbers).
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).
Sequence in context: A022488 A264066 A052157 * A368188 A022470 A080815
KEYWORD
nonn
AUTHOR
EXTENSIONS
Definition corrected by Murphy Waggoner and R. H. Hardin, Sep 24 2013
a(6)-a(8) from R. H. Hardin, Sep 25 2013
a(9)-a(12) from Andrew Howroyd, Feb 03 2021
STATUS
approved

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Last modified March 19 06:05 EDT 2024. Contains 370952 sequences. (Running on oeis4.)