

A257508


Nexttoleaf vertices in binary beanstalk; Numbers n for which A257265(n) = 1.


7



1, 3, 4, 7, 10, 11, 15, 18, 22, 23, 25, 26, 31, 34, 38, 39, 41, 46, 47, 49, 50, 54, 56, 57, 63, 66, 70, 71, 73, 78, 79, 81, 82, 86, 88, 94, 95, 97, 98, 102, 104, 105, 110, 113, 116, 117, 119, 120, 127, 130, 134, 135, 137, 142, 143, 145, 146, 150, 152, 158, 159, 161, 162, 166, 168, 169, 174, 177, 180, 181
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OFFSET

1,2


COMMENTS

Numbers n for which A257265(n) = 1, in other words, numbers n for which a descendant leaf nearest to n in binary beanstalk is one edge away.
Numbers n such that either A079559(A213723(n)) or A079559(A213724(n)) (or both) are zero.
Equal to A257507 with duplicate terms removed.


LINKS

Antti Karttunen, Table of n, a(n) for n = 1..12289
Paul Tek, Illustration of how natural numbers in range 0 .. 133 are organized as a binary tree in the binary beanstalk


EXAMPLE

3 is present because it has an immediate leafchild 5, as A011371(5) = 3.
4 is present because it has an immediate leafchild 6, as A011371(6) = 4.
10 is present because it has two immediate leafchildren, 12 and 13, as A011371(12) = A011371(13) = 10.
See also Paul Tek's illustration.


PROG

(Scheme, with Antti Karttunen's IntSeqlibrary, two alternatives)
(define A257508 (MATCHINGPOS 1 0 (lambda (n) (= 1 (A257265 n)))))
(define A257508 (MATCHINGPOS 1 0 (lambda (n) (or (zero? (A079559 (A213723 n))) (zero? (A079559 (A213724 n))))))) ;; Compare to the definition of A257512.
(Haskell)
a257508 n = a257508_list !! (n1)
a257508_list = filter ((== 1) . a257265) [0..]
 Reinhard Zumkeller, May 06 2015


CROSSREFS

Positions of 1's in A257265.
Subsequence of A005187.
Cf. A011371, A079559, A213723, A213724, A257507, A257509, A257512 (a subsequence).
Sequence in context: A047342 A334469 A228854 * A221975 A340603 A137294
Adjacent sequences: A257505 A257506 A257507 * A257509 A257510 A257511


KEYWORD

nonn


AUTHOR

Antti Karttunen, May 03 2015


STATUS

approved



