A260431 Permutation of natural numbers: a(1) = 1, a(A257804(n)) = 2*a(n), a(A257803(1+n)) = 1 + 2*a(n), where A257804 and A257803 give the positions of even and odd terms in A233271, the infinite trunk of inverted binary beanstalk.

1, 2, 4, 3, 8, 6, 5, 16, 9, 12, 10, 7, 32, 18, 24, 20, 17, 13, 14, 64, 11, 36, 33, 19, 25, 48, 21, 40, 34, 15, 26, 28, 128, 65, 37, 22, 72, 49, 66, 38, 41, 35, 50, 96, 42, 80, 68, 30, 27, 52, 56, 29, 129, 23, 73, 256, 67, 130, 74, 39, 44, 144, 98, 51, 97, 132, 76, 43, 82, 81, 70, 100, 69, 31, 53, 57, 257, 192, 84, 160, 131, 75, 45, 136, 60, 54

Offset

1,2

Links

Antti Karttunen, Table of n, a(n) for n = 1..10000

Index entries for sequences that are permutations of the natural numbers

Formula

a(1) = 1; for n > 1, if A257800(n) = 0 [when n is one of the terms of A257804] a(n) = 2*a(A257808(n)), otherwise [when n is one of the terms of A257803] a(n) = 1 + 2*a(A257807(n)-1).

As a composition of other permutations:

a(n) = A054429(A260433(n)).

a(n) = A260433(A260430(n)).

Prog

(Scheme, with memoizing macro definec)
(definec (A260431 n) (cond ((<= n 1) n) ((zero? (A257800 n)) (* 2 (A260431 (A257808 n)))) (else (+ 1 (* 2 (A260431 (+ -1 (A257807 n))))))))

Crossrefs

Inverse: A260432.

Related permutations: A260433, A260430, A054429.

Cf. A257800, A257803, A257804, A257807, A257808, A233271.

Cf. also A257806.

Sequence in context: A248513 A266414 A245613 * A333484 A334434 A333485

Adjacent sequences: A260428 A260429 A260430 * A260432 A260433 A260434

Keyword

nonn

Author

Antti Karttunen, Jul 27 2015

Status

approved