%I #3 Aug 13 2019 09:03:48
%S 0,0,0,10,2574,748616,282846568,141482705378,93129791442534,
%T 79703248816409088,87547852413089111888,121899005847224540133690,
%U 212656111085108159911203710,459737640779469178164281972792,1218867518038879445116138285206008,3923403293626677106527196012373423122
%N a(n) = A018893(n) - A291973(n).
%p CL := (f, x) -> PolynomialTools:-CoefficientList(f, x):
%p A327002 := proc(n) local P, Q;
%p P := proc(n) option remember; if n = 0 then return 1 fi;
%p add(binomial(3*n, 3*k+3)*P(n-k-1)*x, k=0..n-1) end:
%p Q := proc(n) option remember; if n = 0 then return 1 fi;
%p add(binomial(3*n-1, 3*k)*Q(k)*Q(n-1-k), k=0..n-1) end:
%p Q(n) - add(CL(P(n),x)[k+1]/k!, k=0..n) end:
%p seq(A327002(n), n=0..15);
%Y Cf. A018893, A291973, row 3 of A327000.
%K nonn
%O 0,4
%A _Peter Luschny_, Aug 13 2019