

A140714


Triangle read by rows: T(n,k) is the number of white corners of rank k in all 321avoiding permutations of {1,2,...,n} (n>=2, 0<=k<=n2; for definitions see the ErikssonLinusson references).


0



1, 3, 1, 9, 5, 2, 28, 19, 12, 5, 90, 68, 51, 33, 14, 297, 240, 197, 150, 98, 42, 1001, 847, 735, 609, 466, 306, 132
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OFFSET

2,2


COMMENTS

Sum of entries in row n is 4^(n2) (A000302).


REFERENCES

K. Eriksson and S. Linusson. Combinatorics of Fulton's essential set. Duke Mathematical Journal 85(1):6176, 1996.


LINKS



EXAMPLE

Triangle starts:
1;
3,1;
9,5,2;
28,19,12,5;
90,68,51,33,14;


CROSSREFS



KEYWORD



AUTHOR



STATUS

approved



