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 31-40 of 40 results.

A122287 Signature permutations of FORK-transformations of Catalan automorphisms in table A122204.

Original entry on oeis.org

0, 1, 0, 2, 1, 0, 3, 3, 1, 0, 4, 2, 2, 1, 0, 5, 7, 3, 2, 1, 0, 6, 8, 4, 3, 2, 1, 0, 7, 6, 6, 5, 3, 2, 1, 0, 8, 5, 5, 4, 5, 3, 2, 1, 0, 9, 4, 7, 6, 6, 6, 3, 2, 1, 0, 10, 17, 8, 7, 4, 5, 6, 3, 2, 1, 0, 11, 18, 9, 8, 7, 4, 4, 4, 3, 2, 1, 0, 12, 20, 14, 13, 8, 7, 5, 5, 4, 3, 2, 1, 0, 13, 21, 11, 12, 13
Offset: 0

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Author

Antti Karttunen, Sep 01 2006, Jun 20 2007

Keywords

Comments

Row n is the signature permutation of the Catalan automorphism which is obtained from the n-th automorphism in the table A122204 with the recursion scheme "FORK", or equivalently row n is obtained as FORK(ENIPS(n-th row of A089840)). See A122201 and A122204 for the description of FORK and ENIPS. Moreover, each row of A122287 can be obtained as the "DEEPEN" transform of the corresponding row in A122286. (See A122283 for the description of DEEPEN). Each row occurs only once in this table. Inverses of these permutations can be found in table A122288. This table contains also all the rows of A122201 and A089840.

References

  • A. Karttunen, paper in preparation, draft available by e-mail.

Crossrefs

The first 22 rows of this table: row 0 (identity permutation): A001477, 1: A069767, 2: A057164, 3: A130981, 4: A130983, 5: A130982, 6: A130984, 7: A130986, 8: A130988, 9: A130994, 10: A130992, 11: A130990, 12: A057506, 13: A131004, 14: A131006, 15: A057163, 16: A131008, 17: A131010, 18: A130996, 19: A130998, 20: A131002, 21: A131000. Other rows: 169: A122353, 3617: A057511, 65167: A074681.

A080069 a(n) = A014486(A080068(n)).

Original entry on oeis.org

0, 2, 10, 44, 178, 740, 2868, 11852, 47522, 190104, 735842, 3090116, 11777124, 48557252, 194656036, 778669672, 3117617996, 12677727330, 49850271300, 192901051976, 795560529352, 3243898094388, 12977884832332, 51055591319170
Offset: 0

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Author

Antti Karttunen, Jan 27 2003

Keywords

Comments

Note that A080068 can be also obtained as iteration of A072795 o A057506.

Crossrefs

Same sequence in binary: A080070. Compare with similar Wolframesque plots given in A122229, A122232, A122235, A122239, A122242, A122245, A328111.
Cf. A179758.

Programs

  • Python
    # See attached program

Extensions

Python program and Wolfram-like plot added by Antti Karttunen, Sep 14 2006

A080967 Orbit size of each tree encoded by A014486(n) under Donaghey's "Map M" Catalan automorphism.

Original entry on oeis.org

1, 1, 2, 2, 2, 3, 3, 3, 2, 2, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 2, 2, 6, 6, 6, 3, 6, 3, 2, 6, 3, 6, 5, 6, 6, 6, 6, 3, 5, 6, 6, 5, 6, 6, 6, 5, 5, 3, 6, 3, 6, 3, 6, 2, 6, 3, 3, 6, 6, 6, 6, 6, 2, 2, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 20, 6, 6, 6, 6, 6, 24, 6, 6, 24, 6, 6, 6, 24, 24, 6, 6, 6, 6, 24, 20, 24, 2, 24, 6
Offset: 0

Views

Author

Antti Karttunen, Mar 02 2003

Keywords

Comments

This is the size of the cycle containing n in the permutations A057505/A057506.

Crossrefs

A080292 Orbit size of each tree A080293(n) under Donaghey's "Map M" Catalan automorphism.

Original entry on oeis.org

1, 3, 9, 9, 81, 81, 81, 27, 1701, 1701, 1701, 1701, 2673, 2673, 891, 891
Offset: 0

Views

Author

Antti Karttunen, Mar 02 2003

Keywords

Comments

This is the size of the cycle containing A080295(n) in the permutations A057505/A057506.

Crossrefs

A080977(n) = A080272(2*n)/a(n). A080302(n) = a(n)/3 for n>0. Cf. A080973/A080975.

Formula

a(n) = A080967(A080295(n))

A080972 a(n) = A080969(n)/A080967(A080979(A080970(n))).

Original entry on oeis.org

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

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Author

Antti Karttunen, Mar 02 2003

Keywords

Comments

Donaghey shows in his paper that the orbit size (under the automorphism A057505/A057506) of each non-branch-reduced tree encoded by A080971(n) is divisible by the orbit size of the corresponding branch-reduced tree. This sequence gives the corresponding ratio.

A080981 A014486-encodings of the trees whose interior zigzag-tree (Stanley's c) is branch-reduced (in the sense defined by Donaghey).

Original entry on oeis.org

0, 2, 10, 12, 44, 50, 52, 178, 180, 204, 210, 216, 228, 716, 722, 728, 740, 818, 820, 844, 866, 868, 872, 914, 920, 932, 2866, 2868, 2892, 2914, 2916, 2920, 2962, 2968, 2980, 3276, 3282, 3288, 3300, 3378, 3380, 3468, 3474, 3480, 3490, 3492, 3504, 3528, 3660
Offset: 0

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Author

Antti Karttunen, Mar 02 2003

Keywords

Comments

Donaghey defines (on page 82 of his paper) the branch-reduced zigzag-trees as those zigzag-trees which do not contain longer than one-edge branches, where a branch is a maximal connected set of edges slanted to the same direction, with no perpendicular edges emanating from its middle. These form the primitive elements of the automorphism A057505/A057506.

Crossrefs

a(n) = A014486(A080980(n)). Cf. A080968, A080971. These trees are enumerated by A005554.

Formula

a(n) = A014486(A080980(n)).

A080968 Orbit size of each branch-reduced tree encoded by A080981(n) under Donaghey's "Map M" Catalan automorphism.

Original entry on oeis.org

1, 1, 2, 2, 3, 3, 3, 6, 6, 6, 6, 6, 6, 3, 2, 3, 5, 3, 5, 5, 5, 5, 3, 3, 2, 3, 6, 24, 24, 24, 24, 6, 24, 24, 24, 6, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 6, 24, 24, 24, 24, 24, 6, 24, 24, 6, 3, 18, 9, 24, 18, 18, 9, 18, 9, 18, 18, 3, 24, 15, 15, 24, 24, 18, 15, 15, 24, 3, 24, 24, 15, 15, 24
Offset: 0

Views

Author

Antti Karttunen, Mar 02 2003

Keywords

Comments

This is the size of the cycle containing A080980(n) in the permutations A057505/A057506.
If the conjecture given in A080070 is true, then this sequence contains only six 2's. Questions: are there any (other) values with finite number of occurrences? Which primes will eventually appear?

Crossrefs

Formula

a(n) = A080967(A080980(n))

A215406 A ranking algorithm for the lexicographic ordering of the Catalan families.

Original entry on oeis.org

0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 3, 3, 3, 3, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 5, 5, 5, 5, 5, 5, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4
Offset: 0

Views

Author

Peter Luschny, Aug 09 2012

Keywords

Comments

See Antti Karttunen's code in A057117. Karttunen writes: "Maple procedure CatalanRank is adapted from the algorithm 3.23 of the CAGES (Kreher and Stinson) book."
For all n>0, a(A014486(n)) = n = A080300(A014486(n)). The sequence A080300 differs from this one in that it gives 0 for those n which are not found in A014486. - Antti Karttunen, Aug 10 2012

Crossrefs

Programs

  • Maple
    A215406 := proc(n) local m,a,y,t,x,u,v;
    m := iquo(A070939(n), 2);
    a := A030101(n);
    y := 0; t := 1;
    for x from 0 to 2*m-2 do
        if irem(a, 2) = 1 then y := y + 1
        else u := 2*m - x;
             v := m-1 - iquo(x+y,2);
             t := t + A037012(u,v);
             y := y - 1 fi;
        a := iquo(a, 2) od;
    A014137(m) - t end:
    seq(A215406(i),i=0..199); # Peter Luschny, Aug 10 2012
  • Mathematica
    A215406[n_] := Module[{m, d, a, y, t, x, u, v}, m = Quotient[Length[d = IntegerDigits[n, 2]], 2]; a = FromDigits[Reverse[d], 2]; y = 0; t = 1; For[x = 0, x <= 2*m - 2, x++, If[Mod[a, 2] == 1, y++, u = 2*m - x; v = m - Quotient[x + y, 2] - 1; t = t - Binomial[u - 1, v - 1] + Binomial[u - 1, v]; y--]; a = Quotient[a, 2]]; (1 - I*Sqrt[3])/2 - 4^(m + 1)*Gamma[m + 3/2]*Hypergeometric2F1[1, m + 3/2, m + 3, 4]/(Sqrt[Pi]*Gamma[m + 3]) - t]; Table[A215406[n] // Simplify, {n, 0, 86}] (* Jean-François Alcover, Jul 25 2013, translated and adapted from Peter Luschny's Maple program *)
  • Sage
    def A215406(n) : # CatalanRankGlobal(n)
        m = A070939(n)//2
        a = A030101(n)
        y = 0; t = 1
        for x in (1..2*m-1) :
            u = 2*m - x; v = m - (x+y+1)/2
            mn = binomial(u, v) - binomial(u, v-1)
            t += mn*(1 - a%2)
            y -= (-1)^a
            a = a//2
        return A014137(m) - t

A080272 Orbit size of each tree A080263(n) under Donaghey's "Map M" Catalan automorphism.

Original entry on oeis.org

1, 3, 3, 27, 54, 54, 18, 1134, 1134, 1134, 1134, 1782, 1782, 594, 594, 30618, 30618, 30618, 30618, 78246, 78246, 78246, 78246, 165726, 165726
Offset: 0

Views

Author

Antti Karttunen, Mar 02 2003

Keywords

Comments

This is the size of the cycle containing A080265(n) in the permutations A057505/A057506.

Crossrefs

A080977(n) = a(2*n)/A080292(n).

Formula

a(n) = A080967(A080265(n)).

A080969 Orbit size of each non-branch-reduced tree encoded by A080971(n) under Donaghey's "Map M" Catalan automorphism.

Original entry on oeis.org

2, 2, 2, 6, 6, 6, 6, 6, 6, 2, 2, 6, 6, 6, 3, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 3, 6, 6, 6, 3, 6, 6, 6, 6, 6, 2, 2, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 20, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 20, 2, 6, 6, 6, 20, 20, 6, 6, 6, 6, 6, 20, 6, 6, 20, 6, 20, 6, 6, 20, 20, 6, 20, 6, 6, 6, 20, 20, 6, 6, 20, 20, 6, 20
Offset: 0

Views

Author

Antti Karttunen, Mar 02 2003

Keywords

Comments

This is the size of the cycle containing A080970(n) in the permutations A057505/A057506.

Crossrefs

Formula

a(n) = A080967(A080970(n))
Previous Showing 31-40 of 40 results.