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A347675
Array read by antidiagonals: T(n,k) (n>=1, k>=1) = number of Baxter matrices of size n X k that contain the minimal number of 1's.
3
1, 1, 1, 1, 2, 1, 1, 6, 6, 1, 1, 12, 6, 12, 1, 1, 20, 32, 32, 20, 1, 1, 30, 100, 22, 100, 30, 1, 1, 42, 240, 172, 172, 240, 42, 1, 1, 56, 490, 744, 92, 744, 490, 56, 1, 1, 72, 896, 2364, 956, 956, 2364, 896, 72, 1, 1, 90, 1512, 6174, 5328, 422, 5328, 6174, 1512, 90, 1
OFFSET
1,5
LINKS
Michael S. Branicky, Table of n, a(n) for n = 1..96
Don Knuth, Baxter matrices, Preprint, Sep 05 2021.
FORMULA
a(n) <= A347672(n). - Michael S. Branicky, Sep 15 2021
EXAMPLE
The array begins:
1,1,1,1,1,1,1,...
1,2,6,12,20,30,42,...
1,6,6,32,100,240,490,...
1,12,32,22,172,744,2364,...
1,20,100,172,92,956,5328,...
1,30,240,744,956,422,5492,...
1,42,490,2364,5328,5492,2074,...
...
The first few antidiagonals are:
1,
1,1,
1,2,1,
1,6,6,1,
1,12,6,12,1,
1,20,32,32,20,1,
1,30,100,22,100,30,1,
1,42,240,172,172,240,42,1,
1,56,490,744,92,744,490,56,1,
...
CROSSREFS
The main diagonal is A001181.
Sequence in context: A168641 A255914 A143185 * A157635 A075798 A155864
KEYWORD
nonn,tabl
AUTHOR
N. J. A. Sloane, Sep 10 2021
EXTENSIONS
a(46)-a(66) from Michael S. Branicky, Sep 14 2021
STATUS
approved