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%I #14 Feb 25 2023 18:09:05
%S 1,1,0,1,1,0,1,1,1,0,1,2,2,1,0,1,3,6,3,1,0,1,4,11,11,4,1,0,1,5,22,33,
%T 23,5,1,0,1,7,38,89,96,40,7,1,0,1,8,63,212,345,234,70,8,1,0,1,10,98,
%U 463,1083,1146,546,110,10,1,0,1,12,151,943,3068,4739,3505,1169,176,12,1,0
%N Triangle read by rows: T(n,k) is the number of unlabeled nonseparable (or 2-connected) loopless multigraphs with n edges and k nodes (n >= 1, 2 <= k <= n + 1).
%H Andrew Howroyd, <a href="/A339160/b339160.txt">Table of n, a(n) for n = 1..210</a> (rows 1..20)
%F T(n,2) = T(n,n) = 1.
%e Triangle T(n,k) begins (n edges >= 1, k vertices >= 2):
%e 1;
%e 1, 0;
%e 1, 1, 0;
%e 1, 1, 1, 0;
%e 1, 2, 2, 1, 0;
%e 1, 3, 6, 3, 1, 0;
%e 1, 4, 11, 11, 4, 1, 0;
%e 1, 5, 22, 33, 23, 5, 1, 0;
%e 1, 7, 38, 89, 96, 40, 7, 1, 0;
%e 1, 8, 63, 212, 345, 234, 70, 8, 1, 0;
%e 1, 10, 98, 463, 1083, 1146, 546, 110, 10, 1, 0;
%e 1, 12, 151, 943, 3068, 4739, 3505, 1169, 176, 12, 1, 0;
%e ...
%Y Column k=3 is A001399(n-3).
%Y Row sums are A010357.
%Y Cf. A046752, A191646, A339070.
%K nonn,tabl
%O 1,12
%A _Andrew Howroyd_, Dec 05 2020
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