A361590 Triangle read by rows: T(n,k) is the number of digraphs on n unlabeled nodes with exactly k strongly connected components of size 1.
1, 0, 1, 1, 0, 2, 5, 5, 0, 6, 90, 55, 42, 0, 31, 5289, 2451, 974, 592, 0, 302, 1071691, 323709, 94332, 29612, 15616, 0, 5984, 712342075, 135208025, 25734232, 6059018, 1650492, 795930, 0, 243668, 1585944117738, 181427072519, 21650983294, 3358042412, 704602272, 174576110, 79512478, 0, 20286025
Offset: 0
Examples
Triangle begins: 1; 0, 1; 1, 0, 2; 5, 5, 0, 6; 90, 55, 42, 0, 31; 5289, 2451, 974, 592, 0, 302; 1071691, 323709, 94332, 29612, 15616, 0, 5984; ...