login
A361591
Triangle read by rows: T(n,k) is the number of weakly connected simple digraphs on n labeled nodes with k strongly connected components.
2
1, 0, 1, 0, 1, 2, 0, 18, 18, 18, 0, 1606, 1098, 684, 446, 0, 565080, 263580, 116370, 55620, 26430, 0, 734774776, 225806940, 68822910, 24578010, 9729090, 3596762, 0, 3523091615568, 680637057912, 136498491360, 34626926250, 10819771830, 3694824126, 1111506858
OFFSET
0,6
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..1325 (rows 0..50).
EXAMPLE
Triangle begins:
1;
0, 1;
0, 1, 2;
0, 18, 18, 18;
0, 1606, 1098, 684, 446;
0, 565080, 263580, 116370, 55620, 26430;
0, 734774776, 225806940, 68822910, 24578010, 9729090, 3596762;
...
PROG
(PARI) \\ Uses functions defined in A361455.
T(n)={my(e=2); [Vecrev(p) | p<-Vec(serlaplace(1 + log(U(e, 1/G(e, exp(y*log(U(e, 1/G(e, DigraphEgf(n, e))))))))))]}
{ my(A=T(6)); for(i=1, #A, print(A[i])) }
CROSSREFS
Column k=1 is A003030.
Main diagonal is A082402.
Row sums are A003027.
The unlabeled version is A361587.
Sequence in context: A152154 A324665 A349036 * A261516 A009198 A209123
KEYWORD
nonn,tabl
AUTHOR
Andrew Howroyd, May 04 2023
STATUS
approved