OFFSET
1,2
LINKS
Jim Snyder-Grant, C code to generate and count digraphs with global sinks
Eric Weisstein's World of Mathematics, Digraph Sink
EXAMPLE
For n=3, 18 digraph edge-sets (vertex 0 is the single global sink):
{21,10}
{20,10}
{22,21,10}
{22,20,10}
{21,12,10}
{21,11,10}
{20,12,10}
{22,21,12,10}
{22,21,11,10}
{22,20,12,10}
{22,20,11,10}
{21,20,12,10}
{21,12,11,10}
{20,11,12,10}
{22,21,20,12,10}
{22,21,12,11,10}
{22,20,12,11,10}
{22,21,20,12,11,10}.
PROG
(C) \\ See Jim Snyder-Grant C code to generate and count digraphs with global sinks ./gsinks -l
(PARI) \\ See PARI link in A350794 for program code.
seq(n)={Vec(InitiallyV(GraphCIData(n, DigraphWithLoopEdges)))} \\ Andrew Howroyd, Jan 30 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Jim Snyder-Grant, Jan 30 2022
EXTENSIONS
Terms a(8) and beyond from Andrew Howroyd, Jan 30 2022
STATUS
approved