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.

Showing 1-7 of 7 results.

A083927 Inverse function of N -> N injection A057123.

Original entry on oeis.org

0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 5, 0
Offset: 0

Views

Author

Antti Karttunen, May 13 2003

Keywords

Comments

a(0)=0 because A057123(0)=0, but a(n) = 0 also for those n which do not occur as values of A057123. All positive natural numbers occur here once.
If g(n) = A083927(f(A057123(n))) then we can say that Catalan bijection g embeds into Catalan bijection f in scale n:2n, using the obvious binary tree -> general tree embedding. E.g. we have: A057163 = A083927(A057164(A057123(n))), A057117 = A083927(A072088(A057123(n))), A057118 = A083927(A072089(A057123(n))), A069770 = A083927(A072796(A057123(n))), A072797 = A083927(A072797(A057123(n))).

Links

Crossrefs

a(A057123(n)) = n for all n. Cf. A083925-A083926, A083928-A083929, A083935.

A085169 Permutation of natural numbers induced by the Catalan bijection gma085169 acting on symbolless S-expressions encoded by A014486/A063171.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 8, 7, 9, 10, 11, 13, 12, 14, 15, 19, 22, 21, 16, 18, 17, 20, 23, 24, 25, 27, 26, 28, 29, 33, 36, 35, 30, 32, 31, 34, 37, 38, 39, 41, 40, 51, 52, 60, 64, 63, 56, 59, 58, 62, 42, 43, 47, 50, 49, 44, 46, 45, 48, 53, 55, 54, 61, 57, 65, 66, 67, 69, 68
Offset: 0

Views

Author

Antti Karttunen, Jun 23 2003

Keywords

Comments

A parenthesization is fixed by the Catalan bijections A085169/A085170 if and only if no other elements than () and (()) occur at its top-level: (); ()(),(()); ()()(),()(()),(())(); ()()()(),()()(()),()(())(),(())()(),(())(()); ... There is a simple bijection between these and Zeckendorf-expansions, explaining why Fibonacci numbers gives the number of fixed points of this permutation.
In addition to "rising slope" and "descending slope" mappings from Dyck paths to noncrossing Murasaki-diagrams as illustrated in A085161 and A086431 there is also a mapping where we insert a vertical stick after every second parenthesis and connect those that are on the same level without any intermediate points below. This Catalan bijection converts between these two mappings. See the illustration at example lines.

Examples

			.........................
..._____....________.....
..|.....|..|.....|..|....
..|..|..|..|..|..|..|....
..|..|..|..|..|..|..|....
..|..|..|..|..|..|..|....
..|..|..|..|..|..|..|....
..1((2))3((4((5))6()7))..
...(())(((())()))........
...11001111001000=13256=A014486(368)
To obtain the same Murasaki diagram using the "rising slope mapping" illustrated in A085161, we should use the following Dyck path, encoded by 360th binary string in A014486/A063171:
....___.._____...........
...|...||...|.|..........
...||..|||..|.|..........
...||..|||..|.|..........
...||..||/\.|.|..........
...|/\.|/..\/\/\.........
.../..\/........\........
...11001110010100=13204=A014486(360)
So we have A085169(368)=360 and A085170(360)=368.

Links

Crossrefs

Inverse: A085170. a(n) = A086433(A082853(n))+A082852(n). A074684 = A083925(A085169(A057548(n))). Cf. also A085159, A085160, A085175.
Number of cycles: A086585. Number of fixed points: A000045. Max. cycle size: A086586. LCM of cycle sizes: A086587. (In range [A014137(n-1)..A014138(n-1)] of this permutation).

A083929 Inverse function of N -> N injection A083930.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
Offset: 0

Views

Author

Antti Karttunen, May 13 2003

Keywords

Comments

a(0)=0 because A083930(0)=0, but a(n) = 0 also for those n which do not occur as values of A083930. All positive natural numbers occur here once.
It appears that A071661(n) = A083929(A071663(A083930(n))) and A071662 = A083929(A071664(A083930(n))).

Crossrefs

a(A080930(n)) = n for all n. Cf. A083925-A083928, A083935.

Formula

a(n) = A083927(A083925(n)).

A083935 Inverse function of N -> N injection A083934.

Original entry on oeis.org

0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
Offset: 0

Views

Author

Antti Karttunen, May 13 2003

Keywords

Comments

a(0)=0 because A083934(0)=0, but a(n) = 0 also for those n which do not occur as values of A083934. All positive natural numbers occur here once.

Crossrefs

a(A080934(n)) = n for all n. Cf. A083925-A083929, A014486, A080300, A059905, A059906.

A083928 Inverse function of N -> N injection A080298.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
Offset: 0

Views

Author

Antti Karttunen, May 13 2003

Keywords

Comments

a(1)=0 because A080298(0)=1, but a(n) = 0 also for those n which do not occur as values of A080298. All positive natural numbers occur here once.
For example, A057163 = A083928(A057163(A080298(n))), i.e. Catalan bijection A057163 embeds into itself in scale n:2n+1 using the obvious zigzag-tree -> binary tree embedding.

Links

Crossrefs

a(A080298(n)) = n for all n. Cf. A083925-A083927, A083929, A083935.

A083923 Characteristic function for A057548.

Original entry on oeis.org

0, 1, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
Offset: 0

Views

Author

Antti Karttunen, May 13 2003

Keywords

Links

Crossrefs

a(n) = A083924(A069770(n)). Used to compute A083925.

Formula

a(n) = 1 if A057515(n)=1 (equivalently: if A072772(n)=0), otherwise 0.

A083926 Inverse function of N -> N injection A072795.

Original entry on oeis.org

0, 0, 1, 0, 2, 3, 0, 0, 0, 4, 5, 6, 7, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44
Offset: 0

Views

Author

Antti Karttunen, May 13 2003

Keywords

Comments

a(1)=0 because A072795(0)=1, but a(n) = 0 also for those n which do not occur as values of A072795. All positive natural numbers occur here once.

Crossrefs

a(A072795(n)) = n for all n. Cf. A083925, A083927-A083929, A083935.

Formula

a(n) = A083924(n)*A072772(n).
Showing 1-7 of 7 results.

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