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.

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A072791 Binary widths of A072790.

Original entry on oeis.org

0, 1, 2, 4, 6, 8, 13, 23, 43, 82, 160, 316, 628, 1252, 2500, 4997
Offset: 0

Views

Author

Antti Karttunen, Jun 12 2002

Keywords

Crossrefs

See the comment at A072787. Compare for example with A072641 and A072642.

Extensions

a(12)-a(15) from Sean A. Irvine, Oct 27 2024

A072787 Permutation of natural numbers induced by reranking plane binary trees given in the standard lexicographic order (A014486) with an "arithmetic global ranking algorithm", using A072734 as the packing bijection N X N -> N.

Original entry on oeis.org

0, 1, 3, 2, 6, 5, 13, 8, 4, 14, 10, 36, 20, 9, 25, 19, 24, 11, 12, 18, 38, 16, 7, 44, 27, 209, 77, 21, 105, 66, 104, 28, 35, 65, 230, 54, 15, 34, 33, 75, 43, 26, 85, 50, 40, 37, 22, 31, 191, 67, 23, 51, 41, 69, 107, 68, 49, 92, 30, 29, 32, 56, 211, 46, 17, 299, 120, 5671
Offset: 0

Views

Author

Antti Karttunen, Jun 12 2002

Keywords

Comments

This ranking scheme condenses the structures of the same size (cf. A072789) somewhat better than scheme presented in A072656 (which uses the N X N -> N bijection A072793). Compare the sequences A072790 and A072640 giving the max positions where the last structure with size n will occur in these orderings and the respective binary widths A072791 & A072642. However, by using the second or third power of the bijection A072734 one gets even better results in a certain range.

Links

Crossrefs

Inverse permutation: A072788. Cf. also A014486, A072734, A072789.

A072789 The size of the parenthesizations obtained with the global ranking/unranking scheme presented in A072787-A072788.

Original entry on oeis.org

1, 2, 2, 3, 3, 3, 4, 3, 4, 4, 4, 4, 3, 4, 5, 4, 5, 4, 4, 4, 5, 5, 5, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 4, 5, 4, 6, 5, 5, 6, 5, 5, 6, 5, 6, 6, 5, 5, 5, 6, 6, 5, 6, 5, 6, 6, 6, 6, 6, 6, 6, 6, 5, 5, 5, 5, 5, 6, 6, 6, 6, 7, 5, 6, 5, 6, 6, 6, 7, 6, 6, 7, 5, 6, 7, 7, 6, 6, 6, 5, 6, 7, 6, 7, 7, 6, 6, 7, 7, 7, 6, 5, 5
Offset: 1

Views

Author

Antti Karttunen, Jun 12 2002

Keywords

Comments

To get a cleaner looking table, the term a(0)=0 is not listed here.

Crossrefs

A072790(n) gives the maximum position where the value n occurs. See the comment at A072787. Same triangle computed modulo 2: A072792.
Showing 1-3 of 3 results.

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