%I
%S 1,4,11,23,41,66,99,141,193,256,331,419,521,638,771,921,1089,1276,
%T 1483,1711,1961,2234,2531,2853,3201,3576,3979,4411,4873,5366,5891,
%U 6449,7041,7668,8331,9031,9769,10546
%N Expansion of (1+x^2x^3)/(1x)^4.
%C If Y is a 3subset of an nset X then, for n>=4, a(n4) is the number of (n3)subsets of X which have no exactly one element in common with Y.  _Milan Janjic_, Dec 28 2007
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,6,4,1).
%F a(n3)=binomial(n,3)3*n+9, n=4,5,6,....  _Milan Janjic_, Dec 28 2007
%K nonn,easy
%O 0,2
%A _N. J. A. Sloane_.
