A290611 Number of maximal independent vertex sets (and minimal vertex covers) in the n-tetrahedral graph.

40, 450, 16200, 834960, 80011920, 15710016420

Offset

6,1

Links

Table of n, a(n) for n=6..11.

Eric Weisstein's World of Mathematics, Tetrahedral Graph

Eric Weisstein's World of Mathematics, Maximal Independent Vertex Set

Eric Weisstein's World of Mathematics, Minimal Vertex Cover

Prog

(Python)
from itertools import combinations
from networkx import empty_graph, find_cliques
def A290611(n):
    G = empty_graph(combinations(range(n), 3))
    G.add_edges_from((a, b) for a, b in combinations(G, 2) if len(set(a)&set(b)) != 2)
    return sum(1 for c in find_cliques(G)) # Chai Wah Wu, Jan 16 2024

Crossrefs

Sequence in context: A210355 A210348 A055750 * A115189 A186933 A271650

Adjacent sequences: A290608 A290609 A290610 * A290612 A290613 A290614

Keyword

nonn,more

Author

Eric W. Weisstein, Aug 07 2017

Extensions

a(10) from Eric W. Weisstein, Nov 02 2018

a(11) from Chai Wah Wu, Jan 17 2024

Status

approved