

A112328


a(n)=(n+1)binomial(2n+2,n+1)3*4^n+binomial(2n,n).


1



2, 18, 108, 562, 2724, 12660, 57240, 253842, 1109748, 4798780, 20572392, 87580308, 370706408, 1561573032, 6551178288, 27387484242, 114146434068, 474476717292, 1967642119368, 8142727008732, 33634295542968, 138696447565272
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OFFSET

1,1


COMMENTS

Row sums of A112327.


REFERENCES

F. Ruskey, Average shape of binary trees, SIAM J. Alg. Disc. Meth., 1, 1980, 4350 (Eq. (8)).


LINKS

Table of n, a(n) for n=1..22.


FORMULA

G.f.=4z[2sqrt(14z)]/[(14z)^(3/2)(1+sqrt(14z)]


MAPLE

a:=n>(n+1)*binomial(2*n+2, n+1)3*4^n+binomial(2*n, n): seq(a(n), n=1..25);


CROSSREFS

Cf. A112327.
Sequence in context: A094251 A101570 A006043 * A038721 A064837 A224902
Adjacent sequences: A112325 A112326 A112327 * A112329 A112330 A112331


KEYWORD

nonn


AUTHOR

Emeric Deutsch, Sep 04 2005


STATUS

approved



