

A057547


A014486encodings of Catalan mountain ranges with no sealevel valleys, i.e., the rooted plane general trees with root degree = 1.


5



2, 12, 52, 56, 212, 216, 228, 232, 240, 852, 856, 868, 872, 880, 916, 920, 932, 936, 944, 964, 968, 976, 992, 3412, 3416, 3428, 3432, 3440, 3476, 3480, 3492, 3496, 3504, 3524, 3528, 3536, 3552, 3668, 3672, 3684, 3688, 3696, 3732, 3736, 3748, 3752, 3760
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OFFSET

0,1


COMMENTS

This onetoone correspondence between all rooted plane trees and one node larger, root degree = 1 trees illustrates the fact that INVERT(A000108) = LEFT(A000108). (Catalan numbers shift left under Cameron's A transformation.)


LINKS

Table of n, a(n) for n=0..46.
P. J. Cameron, Some sequences of integers, Discrete Math., 75 (1989), 89102.
P. J. Cameron, Some sequences of integers, in "Graph Theory and Combinatorics 1988", ed. B. Bollobas, Annals of Discrete Math., 43 (1989), 89102.
Index entries for encodings of plane rooted trees


FORMULA

a(n) = A014486(A057548(n)) and also from n > 0 onward = A079946(A014486(n)).
a(n) = alltrees2singletrunked(A014486[n]) (see Maple code below and in A057501).


MAPLE

alltrees2singletrunked := n > pars2binexp([binexp2pars(n)]); # Just surround with extra parentheses.


CROSSREFS

Doubletrunked trees: A057517. Cf. also A057548, A057549.
Sequence in context: A323851 A054667 A009537 * A216648 A043007 A300572
Adjacent sequences: A057544 A057545 A057546 * A057548 A057549 A057550


KEYWORD

nonn,changed


AUTHOR

Antti Karttunen Sep 07 2000


STATUS

approved



