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 1-10 of 15 results. Next

A071665 Permutation A057505 applied four times ("^4"), permutation A071661 squared.

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, 40, 56, 63, 24, 46, 32, 43, 59, 25, 47, 28, 37, 54, 48, 34, 53, 62, 27, 50, 29, 38, 55, 33, 39, 51, 61, 36, 41, 52, 60, 64, 65, 129, 87, 128, 170, 73
Offset: 0

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Author

Antti Karttunen, May 30 2002

Keywords

Crossrefs

Inverse permutation: A071666 and also its car/cdr-flipped conjugate, i.e. A071665(n) = A057163(A071666(A057163(n))) = A057505(A071663(n)) = A071661(A071661(n)). Cf. also A071667, A071669.

A071669 Permutation A057505 applied six times, permutation A071661 cubed, permutation A071663 squared.

Original entry on oeis.org

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

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Author

Antti Karttunen, May 30 2002

Keywords

Comments

Inverse permutation: A071670 and also its car/cdr-flipped conjugate. See formulas.

Crossrefs

Formula

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

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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.

A079437 Number of cycles in range [A014137(n-1)..A014138(n-1)] of permutation A071661.

Original entry on oeis.org

1, 1, 2, 3, 6, 16, 36, 83, 190, 448, 1056, 2514, 5872, 13806, 32424, 76609, 181434, 432062, 1032716
Offset: 0

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Author

Antti Karttunen, Jan 27 2003

Keywords

Comments

That is, number of orbits to which "Catalan bijections" A071661/A071662 partition each A000108(n) Catalan tree structures encoded in A014486[A014137(n-1)..A014138(n-1)].

Crossrefs

Occurs in A073201 as row 13373289.

A079439 Longest cycle in range [A014137(n-1)..A014138(n-1)] of permutation A071661.

Original entry on oeis.org

1, 1, 1, 3, 3, 5, 12, 36, 72, 147, 294, 336, 1068, 5076, 5760, 14742, 58968, 135288, 328176
Offset: 0

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Author

Antti Karttunen, Jan 27 2003

Keywords

Crossrefs

Occurs in A073203 as row 13373289. Cf. A079437, A079438, A079443.

A089403 Least common multiple of all cycle sizes in range [A014137(n-1)..A014138(n-1)] of permutation A071661/A071662.

Original entry on oeis.org

1, 1, 1, 3, 3, 15, 60, 360, 7560, 582120, 7567560, 141965858433999600
Offset: 0

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Author

Antti Karttunen, Nov 29 2003

Keywords

Crossrefs

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))).

A071663 Permutation A057505 applied three times ("cubed").

Original entry on oeis.org

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

Views

Author

Antti Karttunen, May 30 2002

Keywords

Crossrefs

Inverse permutation: A071664 and also its car/cdr-flipped conjugate, i.e. A071663(n) = A057163(A071664(A057163(n))) = A057505(A071661(n)). Cf. also A071665, A071667, A071669.

A071667 Permutation A057505 applied five times ("^5").

Original entry on oeis.org

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

Views

Author

Antti Karttunen, May 30 2002

Keywords

Crossrefs

Inverse permutation: A071668 and also its car/cdr-flipped conjugate, i.e. A071667(n) = A057163(A071668(A057163(n))) = A057505(A071665(n)). Cf. also A071661, A071663, A071669.

A071662 Permutation A057506 applied twice ("squared").

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, 43, 56, 63, 24, 46, 32, 47, 59, 25, 48, 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, May 30 2002

Keywords

Crossrefs

Inverse permutation: A071661 and also its car/cdr-flipped conjugate, i.e. A071662(n) = A057163(A071661(A057163(n))) = A057506(A057506(n)). Cf. also A071664, A071666, A071668, A071670.
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