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.

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.

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))).

A057545 Maximum cycle size in range [A014137(n-1)..A014138(n-1)] of permutation A057505/A057506.

Original entry on oeis.org

1, 1, 2, 3, 6, 6, 24, 72, 144, 147, 588, 672, 2136, 10152, 11520, 29484, 117936, 270576, 656352, 2062368, 4040160
Offset: 0

Views

Author

Antti Karttunen, Sep 07 2000

Keywords

Comments

For the convenience of the range notation above, we define A014137(-1) and A014138(-1) as zero.
Equal to the degree of the polynomials M_n(x) Donaghey gives on the page 81 of his paper.
Factored terms: 1, 1, 2, 3, 2*3, 2*3, 2^3 * 3, 2^3 * 3^2, 2^4 * 3^2, 3 * 7^2, 2^2 * 3 * 7^2, 2^5 * 3 * 7, 2^3 * 3 * 89, 2^3 * 3^3 * 47, 2^8 * 3^2 * 5, 2^2 * 3^4 * 7 * 13, 2^4 * 3^4 * 7 * 13, 2^4 * 3^2 * 1879, 2^5 * 3^2 * 43 * 53, 2^5 * 3^3 * 7 * 11 * 31, 2^5 * 3 * 5 * 19 * 443

Crossrefs

Occurs for first time in A073203 as row 2614.

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))

A080311 Orbit size of each tree encoded by A014486(n) under Meeussen's bf<->df map on binary trees.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 3, 3, 3, 1, 1, 3, 3, 3, 4, 3, 2, 4, 3, 4, 3, 2, 4, 1, 1, 3, 3, 3, 4, 3, 2, 4, 3, 4, 3, 2, 4, 16, 16, 8, 16, 8, 2, 2, 16, 16, 16, 8, 8, 8, 16, 16, 16, 16, 8, 8, 16, 8, 2, 2, 16, 16, 16, 16, 16, 1, 1, 3, 3, 3, 4, 3, 2, 4, 3, 4, 3, 2, 4, 16, 16, 8, 16, 8, 2, 2, 16, 16, 16, 8, 8, 8, 16
Offset: 0

Views

Author

Antti Karttunen, Mar 02 2003

Keywords

Comments

This is the size of the cycle containing n in the permutations A057117/A057118.

Crossrefs

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))

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))
Showing 1-8 of 8 results.