1,3

Index entries for sequences related to rooted trees

sum((-1)^i*(i+1)*binomial(3*n-2*i, n-i)/(2*n-i+1), i=0..n); G.f.: g/(1+zg) where g = 1 + z g^3, g(0) = 1 or g := 2*sin(arcsin(sqrt(27*z)/2)/3)/sqrt(3*z).

Sequence in context: A014623 A144005 A143889 this_sequence A058915 A020054 A117399

Adjacent sequences: A023050 A023051 A023052 this_sequence A023054 A023055 A023056

nonn

Emeric Deutsch (deutsch(AT)duke.poly.edu)