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A269865 Permutation of natural numbers: a(1) = 1, a(2n) = 2*a(n), a(2n+1) = A250469(1+a(n)). 8
1, 2, 3, 4, 5, 6, 9, 8, 7, 10, 15, 12, 11, 18, 27, 16, 25, 14, 21, 20, 13, 30, 45, 24, 17, 22, 33, 36, 23, 54, 81, 32, 19, 50, 75, 28, 35, 42, 63, 40, 55, 26, 39, 60, 37, 90, 135, 48, 49, 34, 51, 44, 29, 66, 99, 72, 41, 46, 69, 108, 91, 162, 243, 64, 85, 38, 57, 100, 125, 150, 225, 56, 31, 70, 105, 84, 47, 126, 189, 80, 43, 110, 165, 52 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

This sequence can be represented as a binary tree. When the parent contains n, the left hand child contains 2n, while the value of right hand child is obtained by applying A250469(1+n):

                                    1

                                    |

                 ................../ \..................

                2                                       3

      4......../ \........5                   6......../ \........9

     / \                 / \                 / \                 / \

    /   \               /   \               /   \               /   \

   /     \             /     \             /     \             /     \

  8       7          10       15         12       11         18       27

16 25   14 21      20  13   30  45     24  17   22  33     36  23   54  81

etc.

Note how all nodes with odd n have a right hand child with value 3n.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..6142

Antti Karttunen, Entanglement Permutations, 2016-2017

Index entries for sequences that are permutations of the natural numbers

FORMULA

a(1) = 1, a(2n) = 2*a(n), a(2n+1) = A250469(1+a(n)).

PROG

(Scheme, with memoization-macro definec)

(definec (A269865 n) (cond ((<= n 1) n) ((even? n) (* 2 (A269865 (/ n 2)))) (else (A250469 (+ 1 (A269865 (/ (- n 1) 2)))))))

CROSSREFS

Inverse: A269866.

Cf. A250469.

Related or similar permutations: A269359, A269863, A269864, A269867, A246375, A249814, A252755, A270195.

Sequence in context: A246376 A269866 A246375 * A269387 A207801 A340364

Adjacent sequences:  A269862 A269863 A269864 * A269866 A269867 A269868

KEYWORD

nonn,tabf,look

AUTHOR

Antti Karttunen, Mar 12 2016

STATUS

approved

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Last modified January 21 22:14 EST 2021. Contains 340354 sequences. (Running on oeis4.)