A039719 Two-dimensional simplicial complexes on n unlabeled nodes.

1, 2, 5, 19, 151

Offset

1,2

Comments

A simplicial complex is a space with a triangulation. Formally, a simplicial complex K in R^n is a collection of simplices of in R^n such that: (1) Every face of a simplex of K is in K, and (2) The intersection of any two simplices of K is a face of each of them (Munkres 1993, p. 7). - Jonathan Vos Post, Feb 03 2011

References

F. Harary and E. M. Palmer, Graphical enumeration, Academic Press, NY, 1973.

V. Jovovic, On the number of two-dimensional simplicial complexes (in Russian), Metody i sistemy tekhnicheskoy diagnostiki, Vypusk 16, Mezhvuzovskiy zbornik nauchnykh trudov, Izdatelstvo Saratovskogo universiteta, 1991, p. 83.

J. R. Munkres, Simplicial Complexes and Simplicial Maps, Section 1.2 in Elements of Algebraic Topology, New York: Perseus Books Pub., pp. 7-14, 1993.

Links

Table of n, a(n) for n=1..5.

Prog

(Magma)
_<x> := PolynomialRing(Rationals()); C := HyperellipticCurve(x^5+2869); [1] cat BadPrimes(C); // Artur Jasinski, May 11 2010

Crossrefs

Sequence in context: A054926 A002786 A304982 * A332653 A198203 A014466

Adjacent sequences: A039716 A039717 A039718 * A039720 A039721 A039722

Keyword

nonn,nice,hard,more

Author

Vladeta Jovovic

Status

approved