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A347679
Irregular triangle read by rows: T(n,k) (1 <= k <= 2*n) = number of n X k Baxter matrices in which all row sums are 2.
2
0, 1, 0, 0, 2, 4, 0, 0, 0, 3, 24, 26, 0, 0, 0, 0, 8, 98, 284, 214, 0, 0, 0, 0, 0, 19, 374, 1922, 3496, 2030, 0, 0, 0, 0, 0, 0, 44, 1342, 10620, 33398, 44674, 21174, 0, 0, 0, 0, 0, 0, 0, 111, 4596, 51904, 245684, 554500, 589092, 236410
OFFSET
1,5
LINKS
Don Knuth, Baxter matrices, Preprint, Sep 05 2021.
EXAMPLE
The T(4,5)=8 matrices of size 4 X 5 are
.
0 0 0 1 1 0 0 0 1 1 0 1 0 0 1 1 0 0 0 1
0 0 1 1 0 1 0 0 1 0 0 0 1 1 0 0 0 1 1 0
0 1 1 0 0 0 1 1 0 0 0 1 0 0 1 0 1 1 0 0
1 1 0 0 0 1 0 0 1 0 1 1 0 0 0 1 0 0 0 1
.
1 0 0 0 1 1 0 0 1 0 1 1 0 0 0 1 1 0 0 0
0 1 1 0 0 0 1 1 0 0 0 1 0 0 1 0 1 1 0 0
0 0 1 1 0 1 0 0 1 0 0 0 1 1 0 0 0 1 1 0
1 0 0 0 1 0 0 0 1 1 0 1 0 0 1 0 0 0 1 1
CROSSREFS
Cf. A347678, A347736 (superdiagonal).
Sequence in context: A107501 A126732 A371648 * A028586 A253179 A300723
KEYWORD
nonn,tabf,more
AUTHOR
N. J. A. Sloane, Sep 10 2021
STATUS
approved