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A202182 Number of n-element unlabeled N-free posets of height k (1 <= k <= n). 1

%I

%S 1,2,5,15,49,180,715,3081,14217,69905,363926,1150036,69269925

%N Number of n-element unlabeled N-free posets of height k (1 <= k <= n).

%D Khamis, Soheir M., Height counting of unlabeled interval and N-free posets. Discrete Math. 275 (2004), no. 1-3, 165-175.

%Y Row sums of A202181.

%Y From the definition, this sequence should be the same as A003430. I do not understand why they differ - possibly a different definition of "N-free"?

%K nonn

%O 1,2

%A _N. J. A. Sloane_, Dec 13 2011

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Last modified May 26 18:08 EDT 2020. Contains 334630 sequences. (Running on oeis4.)