%I #7 Sep 03 2023 10:23:37
%S 2,15,86,634,3956,18549,69065
%N Take n points in general position in space; draw all planes through all triples of these points; sequence gives number of connected regions formed.
%H A. Evnin, <a href="http://www.mathnet.ru/eng/mo412">An elementary Introduction to Matroids</a>, Mathematical Education 2 (33) (2005), 2-33
%F a(n)=1+(n^9-9n^8+6n^7+180n^6-663n^5+369n^4+3536n^3-8964n^2+2952n)/1296
%Y Cf. A055503
%K nonn
%O 3,1
%A _Alexander Evnin_, Dec 26 2008