The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A350608 Number of weakly connected subgraphs of the transitive tournament on {1,...,n}. 3
 1, 1, 4, 31, 474, 14357, 865024, 103931595, 24935913222, 11956100981537, 11460773522931212, 21967828926423843319, 84207961512578582993810, 645554571594493917538073933, 9897742810470352880099047702936, 303505765229448690912596327628571427 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS The transitive tournament on n labeled nodes 1, ..., n has n*(n-1)/2 arcs, namely i->j for 1 <= i < j <= n. REFERENCES Jean Francois Pacault, "Computing the weak components of a directed graph," SIAM Journal on Computing 3 (1974), 56-61. LINKS R. L. Graham, D. E. Knuth, and T. S. Motzkin, Complements and transitive closures, Discrete Mathematics 2 (1972), 17--29. Don Knuth, Weak Components Revived, January 2022. Don Knuth, Pre-Fascicle 12A of TAOCP, Volume 4, January 2022. EXAMPLE a(4)=31: the 31 weakly connected subgraphs when n=4 are the 1+6+15 digraphs that have only 0 or 1 or 2 arcs, plus the four digraphs with three arcs that leave one vertex untouched, plus the five digraphs with three arcs that make an N:   1->3,1->4,2->3;   1->3,1->4,2->4;   1->3,2->3,2->4;   1->4,2->3,2->4;   1->2,1->4,3->4. CROSSREFS Cf. A350609, A350610. Sequence in context: A195195 A141827 A262529 * A143077 A203011 A228467 Adjacent sequences:  A350605 A350606 A350607 * A350609 A350610 A350611 KEYWORD nonn AUTHOR Don Knuth, Jan 16 2022 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 11 03:41 EDT 2022. Contains 356046 sequences. (Running on oeis4.)