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A038018

Triangle: T(n,k), k<=n: groupoids with n elements and k idempotents.

1, 0, 1, 3, 4, 3, 978, 1485, 729, 138, 56630832, 75503872, 37755904, 8390656, 700688, 813802235250650, 1017252851596875

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OFFSET

0,4

LINKS

EXAMPLE

Triangle begins:

0, 1;

3, 4, 3;

978, 1485, 729, 138;

56630832, 75503872, 37755904, 8390656, 700688;

...

CROSSREFS

Row sums are A001329.

Main diagonal is A030247.

Columns k=0..1 are A030250, A030253.

KEYWORD

nonn,tabl,more

AUTHOR

STATUS

approved