%I #11 May 10 2013 12:44:27

%S 30,2310,42840,391545,2375100,10980585,41761720,136963255,399689290,

%T 1060984925,2603641040,5979294230,12973080120,26794003110,53000811600,

%U 100914240770,185718969590,331524753560,575738427880,975199600375,1614655942900,2618302433175

%N Number of labeled pure 2-complexes on n nodes (0-simplexes) with 4 2-simplexes and 12 1-simplexes.

%C 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=4,l=12.

%D 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.

%H T. D. Noe, <a href="/A054647/b054647.txt">Table of n, a(n) for n = 6..1000</a>

%F a(n) = 30*C(n, 6)+2100*C(n, 7)+25200*C(n, 8)+86625*C(n, 9)+116550*C(n, 10)+69300*C(n, 11)+15400*C(n, 12) = n*(n-1)*(n-2)*(n-3)*(n-4)*(n-5)*(n^6+3*n^5-86*n^4-240*n^3+2704*n^2+5232*n-34128)/31104.

%F Empirical G.f.: 5*x^6*(169*x^6-1119*x^5+2535*x^4-1245*x^3-3030*x^2-384*x-6)/(x-1)^13. [_Colin Barker_, Jun 22 2012]

%Y Cf. A054557-A054562.

%K nonn

%O 6,1

%A _Vladeta Jovovic_, Apr 16 2000

%E More terms from _James A. Sellers_, Apr 16 2000