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%I #10 Feb 11 2022 17:14:01
%S 1,1,1,3,1,1,9,4,1,1,30,12,4,1,1,103,45,13,4,1,1,375,160,48,13,4,1,1,
%T 1400,613,175,49,13,4,1,1,5380,2354,680,178,49,13,4,1,1
%N Triangle read by rows: T(n,k) is the number of n-element unlabeled series-parallel posets with k connected components.
%e Triangle begins:
%e 1;
%e 1, 1;
%e 3, 1, 1;
%e 9, 4, 1, 1;
%e 30, 12, 4, 1, 1;
%e 103, 45, 13, 4, 1, 1;
%e 375, 160, 48, 13, 4, 1, 1;
%e 1400, 613, 175, 49, 13, 4, 1, 1;
%e 5380, 2354, 680, 178, 49, 13, 4, 1, 1;
%e ...
%Y Row sums give A003430.
%Y Column 1 is A007453.
%Y Cf. A263864 (all posets), A349488 (disconnected).
%K nonn,tabl
%O 1,4
%A _Salah Uddin Mohammad_, Jan 14 2022
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