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 1-8 of 8 results.

A126317 Number of cycles in range [A014137(n-1)..A014138(n-1)] of permutation A125977/A125978.

Original entry on oeis.org

1, 1, 2, 3, 6, 16, 36, 79, 162, 316, 604, 1204, 2244
Offset: 0

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Author

Antti Karttunen, Jan 16 2007

Keywords

A126318 Maximum cycle size in range [A014137(n-1)..A014138(n-1)] of permutation A125977/A125978.

Original entry on oeis.org

1, 1, 1, 3, 3, 5, 11, 45, 257, 575, 2470, 10892, 30297
Offset: 0

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Author

Antti Karttunen, Jan 16 2007

Keywords

A126319 Least common multiple of all cycle sizes in range [A014137(n-1)..A014138(n-1)] of permutation A125977/A125978.

Original entry on oeis.org

1, 1, 1, 3, 3, 15, 33, 9061920, 1252445414220, 126032376305404800, 50110448042127911907268800, 13399946812028296616282674883512406948355335893125182077721607466200299913000
Offset: 0

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Author

Antti Karttunen, Jan 16 2007

Keywords

A057505 Signature-permutation of a Catalan Automorphism: Donaghey's map M acting on the parenthesizations encoded by A014486.

Original entry on oeis.org

0, 1, 3, 2, 8, 7, 5, 6, 4, 22, 21, 18, 20, 17, 13, 12, 15, 19, 16, 10, 11, 14, 9, 64, 63, 59, 62, 58, 50, 49, 55, 61, 57, 46, 48, 54, 45, 36, 35, 32, 34, 31, 41, 40, 52, 60, 56, 43, 47, 53, 44, 27, 26, 29, 33, 30, 38, 39, 51, 42, 24, 25, 28, 37, 23, 196, 195, 190, 194, 189
Offset: 0

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Author

Antti Karttunen, Sep 03 2000

Keywords

Comments

This is equivalent to map M given by Donaghey on page 81 of his paper "Automorphisms on ..." and also equivalent to the transformation procedure depicted in the picture (23) of Donaghey-Shapiro paper.
This can be also considered as a "more recursive" variant of A057501 or A057503 or A057161.

References

  • D. E. Knuth, The Art of Computer Programming, Volume 4, Fascicle 4: Generating All Trees--History of Combinatorial Generation, vi+120pp. ISBN 0-321-33570-8 Addison-Wesley Professional; 1ST edition (Feb 06, 2006).

Crossrefs

Inverse: A057506.
The 2nd, 3rd, 4th, 5th and 6th "power": A071661, A071663, A071665, A071667, A071669.
Other related permutations: A057501, A057503, A057161.
Cycle counts: A057507. Maximum cycle lengths: A057545. LCM's of all cycles: A060114. See A057501 for other Maple procedures.
Row 17 of table A122288.
Cf. A080981 (the "primitive elements" of this automorphism), A079438, A079440, A079442, A079444, A080967, A080968, A080972, A080272, A080292, A083929, A080973, A081164, A123050, A125977, A126312.

Programs

  • Maple
    map(CatalanRankGlobal,map(DonagheysM, A014486)); or map(CatalanRankGlobal,map(DeepRotateTriangularization, A014486));
    DonagheysM := n -> pars2binexp(DonagheysMP(binexp2pars(n)));
    DonagheysMP := h -> `if`((0 = nops(h)),h,[op(DonagheysMP(car(h))),DonagheysMP(cdr(h))]);
    DeepRotateTriangularization := proc(nn) local n,s,z,w; n := binrev(nn); z := 0; w := 0; while(1 = (n mod 2)) do s := DeepRotateTriangularization(BinTreeRightBranch(n))*2; z := z + (2^w)*s; w := w + binwidth(s); z := z + (2^w); w := w + 1; n := floor(n/2); od; RETURN(z); end;

Formula

a(0) = 0, and for n>=1, a(n) = A085201(a(A072771(n)), A057548(a(A072772(n)))). [This recurrence reflects the S-expression implementation given first in the Program section: A085201 is a 2-ary function corresponding to 'append', A072771 and A072772 correspond to 'car' and 'cdr' (known also as first/rest or head/tail in some languages), and A057548 corresponds to unary form of function 'list'].
As a composition of related permutations:
a(n) = A057164(A057163(n)).
a(n) = A057163(A057506(A057163(n))).

A125976 Signature-permutation of Kreweras' 1970 involution on Dyck paths.

Original entry on oeis.org

0, 1, 3, 2, 8, 6, 5, 7, 4, 22, 19, 15, 20, 14, 13, 11, 18, 21, 16, 10, 12, 17, 9, 64, 60, 52, 61, 51, 41, 39, 55, 62, 53, 38, 40, 54, 37, 36, 33, 29, 34, 28, 50, 47, 59, 63, 56, 43, 48, 57, 42, 27, 25, 32, 35, 30, 46, 49, 58, 44, 24, 26, 31, 45, 23, 196, 191, 178, 192, 177
Offset: 0

Views

Author

Antti Karttunen, Jan 02 2007

Keywords

Comments

Lalanne shows in the 1992 paper that this automorphism preserves the sum of peak heights, i.e., that A126302(a(n)) = A126302(n) for all n. Furthermore, he also shows that A126306(a(n)) = A057514(n)-1 and likewise, that A057514(a(n)) = A126306(n)+1, for all n >= 1.
Like A069772, this involution keeps symmetric Dyck paths symmetric, but not necessarily same.
The number of cycles and fixed points in range [A014137(n-1)..A014138(n-1)] of this involution seem to be given by A007595 and the "aerated" Catalan numbers [1, 1, 0, 1, 0, 2, 0, 5, 0, 14, 0, 42, ...], thus this is probably a conjugate of A069770 (as well as of A057163).

Crossrefs

Compositions and conjugations with other automorphisms: A125977-A125979, A125980, A126290.

Formula

a(n) = A080300(A125974(A014486(n))).

A125978 Signature-permutation of a Catalan automorphism: composition of A125976 and A057163.

Original entry on oeis.org

0, 1, 2, 3, 4, 7, 5, 6, 8, 9, 17, 12, 16, 21, 10, 18, 11, 14, 20, 13, 15, 19, 22, 23, 45, 31, 44, 58, 26, 49, 30, 42, 57, 35, 48, 56, 63, 24, 46, 32, 43, 59, 25, 47, 28, 37, 54, 34, 40, 53, 62, 27, 50, 29, 38, 55, 33, 39, 51, 61, 36, 41, 52, 60, 64, 65, 129, 87, 128, 170, 73
Offset: 0

Views

Author

Antti Karttunen, Jan 02 2007

Keywords

Crossrefs

Inverse: A125977. a(n) = A125976(A057163(n)).

A126312 Fixed points of permutation A071661/A071662.

Original entry on oeis.org

0, 1, 2, 3, 4, 8, 9, 22, 23, 30, 55, 64, 65, 98, 158, 196, 197, 318, 484, 625, 626, 687, 1042, 1549, 1973, 2055, 2056, 2376, 3471, 5113, 6558, 6917, 6918, 8191, 11763, 17268, 22277, 23713, 23714, 24331, 28360, 40491, 59362, 76942, 81754, 82499
Offset: 0

Views

Author

Antti Karttunen, Jan 16 2007

Keywords

Comments

Those i for which A071661(i)=i, i.e. for which A057163(A057164(i)) = A057164(A057163(i)). These appear to consist of just those general plane trees which are symmetric and will stay symmetric also after the underlying plane binary tree has been reflected, i.e. for which A057164(i)=i and A057164(A057163(i)) = A057163(i). See comments at A123050 and A080070. The sequence seems to give also the fixed points of the permutation A125977/A125978.

A125980 Signature-permutation of a Catalan automorphism: A057163-conjugate of A125976.

Original entry on oeis.org

0, 1, 3, 2, 8, 5, 7, 6, 4, 22, 13, 18, 15, 10, 21, 12, 20, 19, 11, 17, 16, 14, 9, 64, 36, 50, 41, 27, 59, 32, 55, 52, 29, 46, 34, 38, 24, 63, 35, 49, 43, 26, 62, 40, 61, 60, 33, 48, 47, 39, 25, 58, 31, 57, 56, 30, 54, 53, 51, 28, 45, 44, 42, 37, 23, 196, 106, 148, 120, 78
Offset: 0

Views

Author

Antti Karttunen, Jan 02 2007

Keywords

Comments

This is self-inverse permutation (involution) of the nonnegative integers.

Crossrefs

Showing 1-8 of 8 results.