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Number of n X n 0..4 matrices with all row and column sums equal.
1

%I #20 Oct 14 2024 11:24:53

%S 1,5,25,1001,790425,11991502235,3632894572698505,

%T 22823286475857170293275,3059096488092534208632573065881,

%U 8933959513305390145234950731901862541009,577809775169956916510410207413319463664222819419555

%N Number of n X n 0..4 matrices with all row and column sums equal.

%e Some solutions for n=3

%e ..4..4..3....2..1..1....2..1..1....4..0..4....1..2..4....3..2..2....3..2..1

%e ..4..3..4....1..3..0....2..0..2....0..4..4....2..3..2....2..1..4....0..3..3

%e ..3..4..4....1..0..3....0..3..1....4..4..0....4..2..1....2..4..1....3..1..2

%Y Column k=4 of A202784.

%K nonn

%O 0,2

%A _R. H. Hardin_, Feb 20 2002

%E Added one term and example - _R. H. Hardin_, Jan 05 2012

%E a(7)-a(8) from _Andrew Howroyd_, Jun 01 2017

%E a(9)-a(10) from _Sean A. Irvine_, Dec 14 2023

%E a(0)=1 prepended by _Andrew Howroyd_, Oct 14 2024