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Triangle read by rows: T(n,k) is the number of unlabeled strongly connected digraphs with n arcs and k vertices, n >= 0, k = 1..n+1.
4

%I #4 Jan 14 2022 19:46:24

%S 1,0,0,0,1,0,0,0,1,0,0,0,2,1,0,0,0,1,4,1,0,0,0,1,16,7,1,0,0,0,0,22,58,

%T 10,1,0,0,0,0,22,240,165,14,1,0,0,0,0,11,565,1281,365,18,1,0,0,0,0,5,

%U 928,6063,4838,733,23,1,0,0,0,0,1,1065,19591,38516,14661,1317,28,1,0

%N Triangle read by rows: T(n,k) is the number of unlabeled strongly connected digraphs with n arcs and k vertices, n >= 0, k = 1..n+1.

%e Triangle begins:

%e 1;

%e 0, 0;

%e 0, 1, 0;

%e 0, 0, 1, 0;

%e 0, 0, 2, 1, 0;

%e 0, 0, 1, 4, 1, 0;

%e 0, 0, 1, 16, 7, 1, 0;

%e 0, 0, 0, 22, 58, 10, 1, 0;

%e 0, 0, 0, 22, 240, 165, 14, 1, 0;

%e 0, 0, 0, 11, 565, 1281, 365, 18, 1, 0;

%o (PARI) \\ See PARI link in A350489 for program code.

%o my(A=A350753rows(10)); for(n=1, #A, print(A[n]))

%Y Row sums are A350752.

%Y Column sums are A035512.

%Y Cf. A057276 (transpose), A350450, A350489.

%K nonn,tabl

%O 0,13

%A _Andrew Howroyd_, Jan 14 2022