A003029 Number of unilaterally connected digraphs with n labeled nodes.

1, 3, 48, 3400, 955860, 1034141596, 4340689156440, 71756043154026904, 4716284688998245793376, 1237457313794197125403483936, 1297922676419612772784598299454784, 5444329780242560941321703550018388707904, 91342929096228825123968637168641318872709897472

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• nice
• easy

References

• V. Jovovic, G. Kilibarda, Enumeration of labeled initially-finally connected digraphs, Scientific review, Serbian Scientific Society, 19-20 (1996), 237-247.
• R. W. Robinson, Counting labeled acyclic digraphs, pp. 239-273 of F. Harary, editor, New Directions in the Theory of Graphs. Academic Press, NY, 1973.
• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

• Andrew Howroyd, Table of n, a(n) for n = 1..50
• V. Jovovic and G. Kilibarda, Enumeration of labeled quasi-initially connected digraphs, Discrete Math., 224 (2000), 151-163.

Crossrefs

The unlabeled version is A003088.

Row sums of A057275.

Cf. A003027, A003028, A003030, A049524, A049414.

Programs

PARI

Unilaterally(12) \\ See A057275. - Andrew Howroyd, Jan 19 2022

Extensions

Corrected and extended by Vladeta Jovovic, Goran Kilibarda

Terms a(12) and beyond from Andrew Howroyd, Jan 11 2022