cp's OEIS Frontend

A361587 Triangle read by rows: T(n,k) is the number of weakly connected digraphs on n unlabeled nodes with k strongly connected components.

%I A361587 #6 Mar 16 2023 19:46:20
%S A361587 1,0,1,0,1,1,0,5,4,4,0,83,56,36,24,0,5048,2406,1101,542,267,0,1047008,
%T A361587 324917,101307,37017,14947,5647,0,705422362,136882286,27757789,
%U A361587 7134897,2257234,779257,237317,0,1580348371788,183851281949,23086772643,3922864504,907027520,258909828,78691767,20035307
%N A361587 Triangle read by rows: T(n,k) is the number of weakly connected digraphs on n unlabeled nodes with k strongly connected components.
%e A361587 Triangle begins:
%e A361587   1;
%e A361587   0,       1;
%e A361587   0,       1,      1;
%e A361587   0,       5,      4,      4;
%e A361587   0,      83,     56,     36,    24;
%e A361587   0,    5048,   2406,   1101,   542,   267;
%e A361587   0, 1047008, 324917, 101307, 37017, 14947, 5647;
%e A361587   ...
%o A361587 (PARI) \\ See PARI link in A350794 for program code.
%o A361587 { my(A=A361587triang(6)); for(n=1, #A, print(A[n])) }
%Y A361587 Column k=1 is A035512.
%Y A361587 Main diagonal is A101228.
%Y A361587 Row sums are A003085.
%Y A361587 Cf. A350794, A361582, A361588.
%K A361587 nonn,tabl
%O A361587 0,8
%A A361587 _Andrew Howroyd_, Mar 16 2023