cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A246678 Permutation of natural numbers: a(1) = 1, a(2n+1) = 1 + 2*a(n), a(2n) = A242378(A001511(n), (1+A000265(n))) - 1.

Original entry on oeis.org

1, 2, 3, 4, 5, 8, 7, 6, 9, 14, 11, 24, 17, 26, 15, 10, 13, 20, 19, 34, 29, 44, 23, 48, 49, 32, 35, 124, 53, 80, 31, 12, 21, 74, 27, 54, 41, 62, 39, 76, 69, 38, 59, 174, 89, 134, 47, 120, 97, 50, 99, 64, 65, 98, 71, 342, 249, 104, 107, 624, 161, 242, 63, 16, 25, 56, 43, 244, 149, 224, 55, 90, 109, 68, 83
Offset: 1

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Author

Antti Karttunen, Sep 01 2014

Keywords

Comments

See the comments in A246676. This is a similar permutation, except for odd numbers, which are here recursively permuted by the emerging permutation itself. The even bisection halved gives A246680, the odd bisection from a(3) onward with one subtracted and then halved gives this sequence back.

Crossrefs

Inverse: A246677.
Variants: A246676, A246684.
Even bisection halved: A246680.

Formula

a(1) = 1, a(2n+1) = 1 + 2*a(n), a(2n) = A242378(A001511(n), (1+A000265(n))) - 1. [Where the bivariate function A242378(k,n) changes each prime p(i) in the prime factorization of n to p(i+k), i.e., it's the result of A003961 iterated k times starting from n].