login
This site is supported by donations to The OEIS Foundation.

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A218788 a(n) = A014486-index for the n-th tendril of infinite beanstalk (A213730(n)), with the "lesser numbers to the right side" construction. 12
0, 0, 0, 0, 1, 0, 0, 1, 3, 0, 0, 0, 1, 3, 0, 4, 0, 0, 1, 0, 0, 1, 3, 0, 4, 0, 0, 1, 4, 0, 0, 2, 0, 3, 1, 0, 0, 0, 1, 3, 0, 4, 0, 0, 1, 4, 0, 0, 2, 0, 3, 1, 0, 4, 0, 0, 2, 0, 37, 0, 0, 110, 0, 3, 0, 1, 0, 0, 1, 3, 0, 4, 0, 0, 1, 4, 0, 0, 2, 0, 3, 1, 0, 4, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,9

COMMENTS

"Tendrils" of the beanstalk are the finite side-trees sprouting from its infinite trunk (see A179016) at the numbers given by A213730.

LINKS

A. Karttunen, Table of n, a(n) for n = 1..8727

A. Karttunen, Illustration of how binary trees (the second rightmost column) are encoded by A014486

EXAMPLE

A213730(9)=22, and from that branches 24 and 25 (as both A011371(24)=A011371(25)=22) and while 24 is a leaf (in A055938) the other branch 25 further branches to two leaves (as both A011371(28)=A011371(29)=25).

When we construct a binary tree from this in such a fashion that the larger numbers go to the left, we obtain:

..........

29...28...

..\./.....

...25..24.

....\./...

.....22...

..........

and the binary tree

.......

.\./...

..*....

...\./.

....*..

.......

is located as A014486(3) in the normal encoding order of binary trees, thus a(9)=3.

PROG

(Scheme with Antti Karttunen's memoization macro definec):

(define (A218788 n) (Aux_for218788 (A213730 n)))

(definec (Aux_for218788 n) (cond ((zero? (A079559 n)) 0) ((not (zero? (A213719 n))) -1) (else (A072764bi (Aux_for218788 (A213724 n)) (Aux_for218788 (A213723 n))))))

CROSSREFS

These are the mirror-images of binary trees given in A218787, i.e. a(n) = A057163(A218787(n)). A218786 gives the sizes of these trees. Cf. A072764, A218610, A218611.

Sequence in context: A290174 A318921 A114516 * A027185 A035641 A242434

Adjacent sequences:  A218785 A218786 A218787 * A218789 A218790 A218791

KEYWORD

nonn

AUTHOR

Antti Karttunen, Nov 11 2012

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 17 18:48 EST 2019. Contains 319251 sequences. (Running on oeis4.)