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

1, 0, 1, 0, 1, 1, 0, 5, 4, 4, 0, 83, 56, 36, 24, 0, 5048, 2406, 1101, 542, 267, 0, 1047008, 324917, 101307, 37017, 14947, 5647, 0, 705422362, 136882286, 27757789, 7134897, 2257234, 779257, 237317, 0, 1580348371788, 183851281949, 23086772643, 3922864504, 907027520, 258909828, 78691767, 20035307

Offset: 0

Author

Andrew Howroyd, Mar 16 2023

Keywords

• nonn
• tabl

Examples

			Triangle begins:
  1;
  0,       1;
  0,       1,      1;
  0,       5,      4,      4;
  0,      83,     56,     36,    24;
  0,    5048,   2406,   1101,   542,   267;
  0, 1047008, 324917, 101307, 37017, 14947, 5647;
  ...
		

Crossrefs

Column k=1 is A035512.

Main diagonal is A101228.

Row sums are A003085.

Cf. A350794, A361582, A361588.

Programs

PARI

\\ See PARI link in A350794 for program code.
{ my(A=A361587triang(6)); for(n=1, #A, print(A[n])) }