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.

A269752 Table of inverse permutations of the rows of A131987: Position of numbers inserted in "storage order" into a perfect binary table of 2^k-1 nodes.

Original entry on oeis.org

1, 2, 1, 3, 4, 2, 6, 1, 3, 5, 7, 8, 4, 12, 2, 6, 10, 14, 1, 3, 5, 7, 9, 11, 13, 15, 16, 8, 24, 4, 12, 20, 28, 2, 6, 10, 14, 18, 22, 26, 30, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 32, 16, 48, 8, 24, 40, 56, 4, 12, 20, 28, 36, 44, 52, 60, 2
Offset: 1

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Author

M. F. Hasler, Mar 04 2016

Keywords

Comments

Row n is the permutation of {1,...,2^n-1} which is the inverse of row n of A131987. See example for an illustration.

Examples

			Row 4 of A131987 is obtained by reading the following binary tree, filled with numbers {1,...,15} in "storage order", from the leftmost to the rightmost number:
       _____1_____
    __2__       __3__
   4     5     6     7
  8 9  10 11 12 13 14 15
This yields the sequence p = (8, 4, 9, 2, 10, 5, 11, 1, 12, 6, 13, 3, 14, 7, 15) which is a permutation of (1, ..., 15). Row 4 of the present table yields the inverse permutation p' = (8, 4, 12, 2, 6, 10, 14, 1, 3, 5, 7, 9, 11, 13, 15), where p'(i) is the index of i in p, e.g. p'(3)=12 because 3 = p(12).
		

Programs