A054561 Number of labeled pure 2-complexes on n nodes (0-simplexes) with 5 2-simplexes and 12 1-simplexes.

2700, 118020, 1220520

Offset

6,1

Comments

Number of {T_1,T_2,...,T_k} where T_i,i=1..k are 3-subsets of an n-set such that {D | D is 2-subset of T_i for some i=1..k} has l elements; k=5,l=12.

References

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.

Links

Table of n, a(n) for n=6..8.

Formula

a(n)=2700*C(n, 6)+99120*C(n, 7)+351960*C(n, 8)+...

Crossrefs

Cf. A054557.

Sequence in context: A254805 A254798 A253814 * A230752 A364795 A246888

Adjacent sequences: A054558 A054559 A054560 * A054562 A054563 A054564

Keyword

more,nonn,bref

Author

Vladeta Jovovic, Apr 10 2000

Status

approved