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A202178 Triangle read by rows: T(n,k) = number of n-element unlabeled connected N-free posets of height k (1 <= k <= n).

%I A202178 #11 Jun 08 2020 05:23:58
%S A202178 1,0,1,0,2,1,0,3,5,1,0,4,17,9,1,0,5,45,50,14,1,0,6,115,218,114,20,1,0,
%T A202178 7,278,851,709,224,27,1,0,8,679,3161,3818,1867,398,35,1,0,9,1666,
%U A202178 11507,19042,13113,4276,657,44,1,0,10,4167,41837,91383,83222,37898,8845,1025,54,1
%N A202178 Triangle read by rows: T(n,k) = number of n-element unlabeled connected N-free posets of height k (1 <= k <= n).
%H A202178 Soheir M. Khamis, <a href="https://doi.org/10.1016/S0012-365X(03)00106-7">Height counting of unlabeled interval and N-free posets</a>, Discrete Math. 275 (2004), no. 1-3, 165-175.
%e A202178 Triangle begins:
%e A202178 1
%e A202178 0 1
%e A202178 0 2 1
%e A202178 0 3 5 1
%e A202178 0 4 17 9 1
%e A202178 0 5 45 50 14 1
%e A202178 0 6 115 218 114 20 1
%e A202178 0 7 278 851 709 224 27 1
%e A202178 0 8 679 3161 3818 1867 398 35 1
%e A202178 0 9 1666 11507 19042 13113 4276 657 44 1
%e A202178 0 10 4167 41837 91383 83222 37898 8845 1025 54 1
%e A202178 ...
%Y A202178 See A202179 for another version. Row sums give A202180.
%K A202178 nonn,tabl
%O A202178 1,5
%A A202178 _N. J. A. Sloane_, Dec 13 2011