1,2

M. Klazar, Twelve countings with rooted plane trees, European Journal of Combinatorics 18 (1997), 195-210; Addendum, 18 (1997), 739-740.

F. Ruskey, "Listing and Counting Subtrees of a Tree", SIAM J. Computing, 10 (1981) 141-150.

Index entries for sequences related to rooted trees

Index entries for reversions of series

G.f.: A(z) = (1-B(z)-sqrt(1-5z-B(z)))/2, where B(z) = (1-sqrt(1-4z))/2.

a[ 1 ] = 1 and for n > 1 a[ n ] = sum( (a[ j ]+b[ j ])*a[ n-j ], j=1..n-1 ), where b[ n ] = C(2n-2, n-1)/n (Catalan number).

Also REVERT[A(x)] = x + 2*x^2 + x^3*(A007440(x) (Reversion of Fibonacci) - Olivier Gerard (olivier.gerard(AT)gmail.com), Jul 05 2001

a(n+1)=Sum_{k, 0<=k<=n}A039599(n,k)*A000108(k). - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Mar 12 2007

Cf. A007440.

Adjacent sequences: A007849 A007850 A007851 this_sequence A007853 A007854 A007855

Sequence in context: A126568 A054321 A132262 this_sequence A110576 A074600 A064641

nonn

Martin Klazar (klazar(AT)kam.mff.cuni.cz)

More terms and formulae from fruskey(AT)cs.uvic.ca (Frank Ruskey), 11/97.