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.

A227351 Permutation of nonnegative integers: map each number by lengths of runs of zeros in its Zeckendorf expansion shifted once left to the number which has the same lengths of runs (in the same order, but alternatively of runs of 0's and 1's) in its binary representation.

Original entry on oeis.org

0, 1, 3, 7, 2, 15, 6, 4, 31, 14, 12, 8, 5, 63, 30, 28, 24, 13, 16, 9, 11, 127, 62, 60, 56, 29, 48, 25, 27, 32, 17, 19, 23, 10, 255, 126, 124, 120, 61, 112, 57, 59, 96, 49, 51, 55, 26, 64, 33, 35, 39, 18, 47, 22, 20, 511, 254, 252, 248, 125, 240, 121, 123, 224
Offset: 0

Views

Author

Antti Karttunen, Jul 08 2013

Keywords

Comments

This permutation is based on the fact that by appending one extra zero to the right of Fibonacci number representation of n (aka "Zeckendorf expansion") and then counting the lengths of blocks of consecutive (nonleading) zeros we get bijective correspondence with compositions, and thus also with the binary representation of a unique n. See the chart below:
n A014417(n) A014417(A022342(n+1)) Runs of Binary number In dec.
[shifted once left] zeros with same runs = a(n)
0: ......0 ......0 [] .....0 0
1: ......1 .....10 [1] .....1 1
2: .....10 ....100 [2] ....11 3
3: ....100 ...1000 [3] ...111 7
4: ....101 ...1010 [1,1] ....10 2
5: ...1000 ..10000 [4] ..1111 15
6: ...1001 ..10010 [2,1] ...110 6
7: ...1010 ..10100 [1,2] ...100 4
8: ..10000 .100000 [5] .11111 31
9: ..10001 .100010 [3,1] ..1110 14
10: ..10010 .100100 [2,2] ..1100 12
11: ..10100 .101000 [1,3] ..1000 8
12: ..10101 .101010 [1,1,1] ...101 5
13: .100000 1000000 [6] 111111 63
Are there any other fixed points after 0, 1, 6, 803, 407483 ?

Crossrefs

Inverse permutation: A227352. Cf. also A003714, A014417, A006068, A048679.
Could be further composed with A075157 or A075159, also A129594.

Programs

Formula

a(n) = A006068(A048679(n)) = A006068(A106151(2*A003714(n))).
This permutation effects following correspondences:
a(A000045(n)) = A000225(n-1).
a(A027941(n)) = A000975(n).
For n >=3, a(A000204(n)) = A000079(n-2).