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A126303 a(n) = number of nodes with odd distance to the root in the n-th plane general tree encoded by A014486(n). Both internal and terminal nodes (leaves) are counted. 4
0, 1, 2, 1, 3, 2, 2, 1, 2, 4, 3, 3, 2, 3, 3, 2, 2, 1, 2, 3, 2, 3, 2, 5, 4, 4, 3, 4, 4, 3, 3, 2, 3, 4, 3, 4, 3, 4, 3, 3, 2, 3, 3, 2, 2, 1, 2, 3, 2, 3, 2, 4, 3, 3, 2, 3, 4, 3, 4, 3, 3, 2, 3, 2, 3, 6, 5, 5, 4, 5, 5, 4, 4, 3, 4, 5, 4, 5, 4, 5, 4, 4, 3, 4, 4, 3, 3, 2, 3, 4, 3, 4, 3, 5, 4, 4, 3, 4, 5, 4, 5, 4 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..101.

EXAMPLE

A014486(27) = 696 (1010111000 in binary), encodes the following general plane tree, where the root is marked with * and nodes with even or odd distance to root with 'e's and 'o's, respectively.

.......o

.......|

.......e

.......|

...o.o.o

....\|/.

.....*..

there are four nodes marked with 'o', thus a(27)=4.

PROG

(MIT Scheme:) (define (A126303 n) (*A126303 (A014486->parenthesization (A014486 n))))

(define (*A126303 s) (cond ((null? s) 0) (else (fold-left (lambda (x y) (+ x 1 (*A126304 y))) 0 s))))

CROSSREFS

a(n) = A072643(n)-A126305(n). Cf. A126304. Scheme-function A014486->parenthesization given in A014486.

Sequence in context: A090000 A109082 A324923 * A306467 A157810 A072339

Adjacent sequences:  A126300 A126301 A126302 * A126304 A126305 A126306

KEYWORD

nonn

AUTHOR

Antti Karttunen, Jan 02 2007

STATUS

approved

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Last modified May 19 23:16 EDT 2019. Contains 323411 sequences. (Running on oeis4.)