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A054561 Number of labeled pure 2-complexes on n nodes (0-simplexes) with 5 2-simplexes and 12 1-simplexes. 0
2700, 118020, 1220520 (list; graph; refs; listen; history; text; internal format)
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 A246888 A153513

Adjacent sequences:  A054558 A054559 A054560 * A054562 A054563 A054564

KEYWORD

more,nonn,bref

AUTHOR

Vladeta Jovovic, Apr 10 2000

STATUS

approved

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Last modified September 27 15:29 EDT 2020. Contains 337383 sequences. (Running on oeis4.)