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.

Previous Showing 41-49 of 49 results.

A122300 Row 2 of A122283 and A122284. An involution of nonnegative integers.

Original entry on oeis.org

0, 1, 2, 3, 4, 6, 5, 7, 8, 9, 10, 14, 16, 19, 11, 15, 12, 17, 20, 13, 18, 21, 22, 23, 24, 25, 26, 27, 37, 38, 42, 44, 53, 51, 47, 56, 60, 28, 29, 39, 43, 52, 30, 40, 31, 45, 46, 34, 54, 57, 61, 33, 41, 32, 48, 55, 35, 49, 58, 62, 36, 50, 59, 63, 64, 65, 66, 67, 68, 69, 70, 71
Offset: 0

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Author

Antti Karttunen, Sep 01 2006

Keywords

Comments

The signature-permutation of the automorphism which is derived from the second non-recursive automorphism *A072796 either with recursion schema DEEPEN or NEPEED. (see A122283, A122284 for their definitions).

Crossrefs

A123714 Signature permutation of a nonrecursive Catalan automorphism: row 1786785 of table A089840.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 8, 6, 7, 9, 10, 11, 12, 13, 21, 22, 19, 14, 15, 20, 16, 17, 18, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 58, 59, 62, 63, 64, 56, 60, 51, 37, 38, 52, 39, 40, 41, 57, 61, 53, 42, 43, 54, 44, 45, 46, 55, 47, 48, 49, 50, 65, 66, 67, 68, 69, 70, 71
Offset: 0

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Author

Antti Karttunen, Oct 11 2006

Keywords

Comments

This automorphism is illustrated below, where letters A, B, C, D, E and F refer to arbitrary subtrees located on those nodes and () stands for an implied terminal node.
.............................B...C............F...B......
..............................\./..............\./.......
...............................x...D............x...C....
................................\./..............\./.....
.................................x...E............x...D..
..................................\./.....-->......\./...
..A...B.........C...A..............x...F............x...E
...\./...........\./................\./..............\./.
....x...C...-->...x...B..........()..x............()..x..
.....\./...........\./............\./..............\./...
......x.............x..............x................x....
This is the last multiclause automorphism of total seven opened conses in the table A089840. The next nonrecursive automorphism, A089840[1786786], which consists of a single seven-node clause, swaps the first two toplevel elements (of a general plane tree, like *A072796 does), but only if A057515(n) > 6 and in other cases keeps the tree intact.

Crossrefs

Inverse: A123713. Row 1786785 of A089840. Differs from A089857 for the first time at n=102, where a(n)=106, while A089857(n)=102.

A129605 Signature-permutation of a Catalan automorphism, row 3613 of A089840.

Original entry on oeis.org

0, 1, 2, 3, 4, 6, 5, 7, 8, 9, 11, 14, 16, 19, 10, 15, 12, 17, 18, 13, 20, 21, 22, 23, 24, 28, 30, 33, 37, 39, 42, 44, 47, 51, 53, 56, 60, 25, 29, 38, 43, 52, 26, 40, 31, 45, 46, 32, 48, 49, 50, 27, 41, 34, 54, 55, 35, 57, 58, 59, 36, 61, 62, 63, 64, 65, 66, 67, 68, 69, 79, 80
Offset: 0

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Author

Antti Karttunen, May 22 2007

Keywords

Comments

This involution effects the following transformation on the binary trees (labels A,B,C,D refer to arbitrary subtrees located on those nodes and () stands for a terminal node.)
.....C...D.........A...D
......\./...........\./
...B...X2........C...Y2......B..().......A..()
....\./...........\./.........\./.........\./
.A...X1....-->.B...Y1......A...X1..-->.B...Y1
..\./...........\./.........\./.........\./
...X0............Y0..........X0..........Y0
Note that automorphism *A072796 = SPINE(*A129605). See the definition given in A122203.

Crossrefs

Inverse: A129606.

A129606 Signature-permutation of a Catalan automorphism, row 3613 of A089840.

Original entry on oeis.org

0, 1, 2, 3, 4, 6, 5, 7, 8, 9, 14, 10, 16, 19, 11, 15, 12, 17, 18, 13, 20, 21, 22, 23, 24, 37, 42, 51, 25, 38, 26, 44, 47, 27, 53, 56, 60, 28, 39, 29, 43, 52, 30, 40, 31, 45, 46, 32, 48, 49, 50, 33, 41, 34, 54, 55, 35, 57, 58, 59, 36, 61, 62, 63, 64, 65, 66, 67, 68, 69, 107
Offset: 0

Views

Author

Antti Karttunen, May 22 2007

Keywords

Comments

This involution effects the following transformation on the binary trees (labels A,B,C,D refer to arbitrary subtrees located on those nodes and () stands for a terminal node.)
.....C...D.........B...D
......\./...........\./
...B...X2........A...Y2......B..().......A..()
....\./...........\./.........\./.........\./
.A...X1....-->.C...Y1......A...X1..-->.B...Y1
..\./...........\./.........\./.........\./
...X0............Y0..........X0..........Y0
Note that automorphism *A072796 = ENIPS(*A129606). See the definition given in A122204.

Crossrefs

Inverse: A129605.

A129607 Signature-permutation of a Catalan automorphism: swap the left and right subtree of degree 2 general trees.

Original entry on oeis.org

0, 1, 2, 3, 4, 6, 5, 7, 8, 9, 10, 11, 16, 19, 14, 15, 12, 17, 18, 13, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 44, 47, 33, 53, 56, 60, 37, 38, 39, 43, 52, 42, 40, 31, 45, 46, 32, 48, 49, 50, 51, 41, 34, 54, 55, 35, 57, 58, 59, 36, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71
Offset: 0

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Author

Antti Karttunen, May 22 2007

Keywords

Comments

Otherwise like automorphism *A072796, except that this involution exchanges the two leftmost subtrees of a general tree ONLY when the degree of the tree is two. Automorphism *A129608 = SPINE(*A129607) = ENIPS(*A129607). See the definitions given in A122203 and A122204.

Crossrefs

Row 3608 of A089840.

A130340 Signature permutation of a Catalan automorphism: swap the two leftmost subtrees of general trees, if the root degree (A057515(n)) is even.

Original entry on oeis.org

0, 1, 2, 3, 4, 6, 5, 7, 8, 9, 10, 11, 16, 19, 14, 15, 12, 17, 18, 13, 20, 21, 22, 23, 24, 25, 26, 27, 37, 29, 30, 44, 47, 33, 53, 56, 60, 28, 38, 39, 43, 52, 42, 40, 31, 45, 46, 32, 48, 49, 50, 51, 41, 34, 54, 55, 35, 57, 58, 59, 36, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71
Offset: 0

Views

Author

Antti Karttunen, Jun 05 2007

Keywords

Comments

This is a self-inverse automorfism (an involution). Can be used to construct A130373.

Crossrefs

Cf. a(n) = A057508(A130339(A057508(n))) = A057164(A130339(A057164(n))). a(n) = A072796(n), if A057515(n) mod 2 = 0, otherwise a(n)=n.

A122363 Row 2 of A122289.

Original entry on oeis.org

0, 1, 2, 3, 4, 6, 5, 7, 8, 9, 10, 14, 16, 19, 11, 15, 12, 17, 18, 13, 20, 21, 22, 23, 28, 25, 26, 27, 37, 38, 42, 44, 47, 51, 53, 56, 60, 24, 29, 39, 43, 52, 30, 40, 31, 45, 54, 34, 48, 49, 50, 33, 41, 32, 46, 55, 35, 57, 58, 62, 36, 61, 59, 63, 64, 65, 67, 79, 84, 93, 66, 81
Offset: 0

Views

Author

Antti Karttunen, Sep 01 2006

Keywords

Comments

The signature-permutation of the automorphism which is derived from the second non-recursive automorphism *A072796 with FORK(FORK(*A072796)) = FORK(*A057511). (see A122201 for the definition of FORK).

Crossrefs

Inverse: A122364.

A122364 Row 2 of A122290.

Original entry on oeis.org

0, 1, 2, 3, 4, 6, 5, 7, 8, 9, 10, 14, 16, 19, 11, 15, 12, 17, 18, 13, 20, 21, 22, 23, 37, 25, 26, 27, 24, 38, 42, 44, 53, 51, 47, 56, 60, 28, 29, 39, 43, 52, 30, 40, 31, 45, 54, 32, 48, 49, 50, 33, 41, 34, 46, 55, 35, 57, 58, 62, 36, 61, 59, 63, 64, 65, 70, 66, 121, 149, 107
Offset: 0

Views

Author

Antti Karttunen, Sep 01 2006

Keywords

Comments

The signature-permutation of the automorphism which is derived from the second non-recursive automorphism *A072796 with KROF(KROF(*A072796)) = KROF(*A057512). (see A122202 for the definition of KROF).

Crossrefs

Inverse: A122363.

A130374 Signature permutation of a Catalan automorphism: flip the positions of even- and odd-indexed elements at the top level of the list, leaving the last element in place if the length (A057515(n)) is odd.

Original entry on oeis.org

0, 1, 2, 3, 4, 6, 5, 7, 8, 9, 10, 14, 16, 19, 11, 15, 12, 17, 18, 13, 20, 21, 22, 23, 25, 24, 26, 27, 37, 38, 42, 44, 47, 51, 53, 56, 60, 28, 29, 39, 43, 52, 30, 40, 31, 45, 46, 32, 48, 49, 50, 33, 41, 34, 54, 55, 35, 57, 58, 59, 36, 61, 62, 63, 64, 65, 66, 70, 72, 75, 67, 71
Offset: 0

Views

Author

Antti Karttunen, Jun 05 2007

Keywords

Comments

This self-inverse automorphism permutes the top level of a list of even length (1 2 3 4 ... 2n-1 2n) as (2 1 4 3 ... 2n 2n-1), and when applied to a list of odd length (1 2 3 4 ... 2n-1 2n 2n+1), permutes it as (2 1 4 3 ... 2n 2n-1 2n+1).

Crossrefs

Cf. a(n) = A057508(A130373(A057508(n))) = A057164(A130373(A057164(n))) = A127285(A127288(n)) = A127287(A127286(n)). Also a(A085223(n)) = A130370(A122282(A130369(A085223(n)))) holds for all n>=0. The number of cycles and the number of fixed points in range [A014137(n-1)..A014138(n-1)] of this permutation are given by A073193 and A073192.
Previous Showing 41-49 of 49 results.