A003029 Number of unilaterally connected digraphs with n labeled nodes. (Formerly M3156)

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

Offset

1,2

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.

Prog

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

Crossrefs

The unlabeled version is A003088.

Row sums of A057275.

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

Sequence in context: A356612 A295813 A326217 * A049524 A270748 A322363

Adjacent sequences: A003026 A003027 A003028 * A003030 A003031 A003032

Keyword

nonn,nice,easy

Author

N. J. A. Sloane

Extensions

Corrected and extended by Vladeta Jovovic, Goran Kilibarda

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

Status

approved