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 70 results. Next

A060126 Positions of permutations of A055089 in the permutation sequence A060117.

Original entry on oeis.org

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

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Author

Antti Karttunen, Mar 02 2001

Keywords

Comments

Together with the inverse A060119 this can be used to conjugate between "multiplication tables" of A261096 & A261216 (and for example, their main diagonals A261099 & A261219, or between involutions A056019 & A060125, see the Formula section) that have been computed for these two common alternative orderings of permutations. - Antti Karttunen, Sep 28 2016

Crossrefs

Inverse: A060119.
Cf. A060132 (fixed points).

Programs

  • Maple
    # Procedure PermRank3R is given in A060125 and PermRevLexUnrank in A055089:
    A060126(n) = PermRank3R(PermRevLexUnrank(n));

Formula

Other identities. For all n >= 0:
a(A056019(A060119(n))) = A060125(n).

Extensions

Edited by Antti Karttunen, Sep 28 2016

A060119 Positions of permutations of A060117 in reversed colexicographic ordering A055089.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Mar 02 2001

Keywords

Comments

Together with the inverse A060126 this can be used to conjugate between "multiplication tables" of A261096 & A261216 (and for example, their main diagonals A261099 & A261219, or between involutions A056019 & A060125, see the Formula section) that have been computed for these two common alternative orderings of permutations. - Antti Karttunen, Sep 28 2016

Crossrefs

Inverse: A060126.
Cf. A060132 (fixed points).

Programs

  • Maple
    # The procedure PermUnrank3R is given in A060117, and PermRevLexRank in A056019:
    A060119(n) = PermRevLexRank(PermUnrank3R(n));

Formula

As a composition of other permutations:
a(n) = A056019(A060120(n)).
Other identities, for all n >= 0:
a(A060125(A060126(n))) = A056019(n).

Extensions

Edited by Antti Karttunen, Sep 27 2016

A056019 Self-inverse infinite permutation which shows the position of each finite permutation's inverse permutation in A055089.

Original entry on oeis.org

0, 1, 2, 4, 3, 5, 6, 7, 12, 18, 13, 19, 8, 10, 14, 20, 16, 22, 9, 11, 15, 21, 17, 23, 24, 25, 26, 28, 27, 29, 48, 49, 72, 96, 73, 97, 50, 52, 74, 98, 76, 100, 51, 53, 75, 99, 77, 101, 30, 31, 36, 42, 37, 43, 54, 55, 78, 102, 79, 103, 60, 66, 84, 108, 90, 114, 61, 67, 85
Offset: 0

Views

Author

Antti Karttunen, Jun 08 2000

Keywords

Comments

PermRevLexRank and PermRevLexUnrank have been modified from the algorithms PermLexRank and PermLexUnrank presented in the book "Combinatorial Algorithms, Generation, Enumeration and Search", by Donald L. Kreher and Douglas R. Stinson.

Examples

			E.g. the permutation [2,3,1] is the 4th permutation (counting from 0th, the identity permutation) of A055089, its inverse permutation is [3,1,2] which is 3rd, thus a(4)=3 and a(3)=4.
		

Programs

  • Maple
    PermRevLexRank := proc(pp) local p,n,i,j,r; p := pp; n := nops(p); r := 0; for j from n by -1 to 1 do r := r + (((j-p[j])*((j-1)!))); for i from 1 to (j-1) do if(p[i] > p[j]) then p[i] := p[i]-1; fi; od; od; RETURN(r); end;
    [seq(PermRevLexRank(convert(invperm(convert(PermRevLexUnrank(j), 'disjcyc')), 'permlist', nops(PermRevLexUnrank(j)))), j=0..200)];
  • Mathematica
    A056019 = Position[Ordering /@ #, #[[#2]]][[1, 1]] - 1 &[Reverse@SortBy[Permutations@Range@Ceiling@InverseFunction[Factorial][# + 1], Reverse], # + 1] &; Array[A056019, 69, 0] (* JungHwan Min, Oct 10 2016 *)
    A056019L = Ordering[Ordering /@ Permutations@Range@Ceiling@InverseFunction[Factorial][# + 1]] - 1 &; A056019L[24] (* JungHwan Min, Oct 10 2016 *)

A060120 Positions of permutations of A060118 in the canonical permutation list A055089.

Original entry on oeis.org

0, 1, 2, 4, 5, 3, 6, 7, 12, 18, 19, 13, 14, 20, 8, 10, 16, 22, 21, 15, 23, 17, 11, 9, 24, 25, 26, 28, 29, 27, 48, 49, 72, 96, 97, 73, 74, 98, 50, 52, 76, 100, 99, 75, 101, 77, 53, 51, 54, 55, 78, 102, 103, 79, 30, 31, 36, 42, 43, 37, 60, 66, 84, 108, 114, 90, 67, 61, 91
Offset: 0

Views

Author

Antti Karttunen, Mar 02 2001

Keywords

Crossrefs

PermRevLexRank given in A056019. A060120[n] = A056019[A060119[n]] for all n.
Inverse permutation: A060127.

Formula

a(n) = PermRevLexRank(PermUnrank3L(n))

A055091 Minimum number of transpositions needed to represent each permutation given in reversed colexicographic ordering A055089.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Apr 18 2000

Keywords

Crossrefs

Cf. also A034968 (minimum number of adjacent transpositions).

Programs

  • Maple
    with(group); [seq(count_transpositions(convert(PermRevLexUnrank(j),'disjcyc')),j=0..)];
    count_transpositions := proc(l) local c,t; t := 0; for c in l do t := t + (nops(c)-1); od; RETURN(t); end;
    # Procedure PermRevLexUnrank given in A055089.

Formula

a(n) = A055093(n) - A055090(n).
a(n) = A046660(A290095(n)) = A060130(A060126(n)). - Antti Karttunen, Dec 30 2017

Extensions

Entry revised by Antti Karttunen, Dec 30 2017

A055093 Number of moved (non-fixed) elements in each permutation given in reversed colexicographic ordering A055089, i.e., the sum of their cycle lengths (excluding the 1-cycles, i.e., fixed elements).

Original entry on oeis.org

0, 2, 2, 3, 3, 2, 2, 4, 3, 4, 4, 3, 3, 4, 2, 3, 4, 4, 4, 3, 3, 2, 4, 4, 2, 4, 4, 5, 5, 4, 3, 5, 4, 5, 5, 4, 4, 5, 3, 4, 5, 5, 5, 4, 4, 3, 5, 5, 3, 5, 4, 5, 5, 4, 2, 4, 3, 4, 4, 3, 4, 5, 4, 5, 5, 5, 5, 4, 5, 4, 5, 5, 4, 5, 3, 4, 5, 5, 3, 4, 2, 3, 4, 4, 4, 5, 4, 5, 5, 5, 5, 5, 5, 5, 4, 4, 5, 4, 4, 3, 5, 5, 4, 3, 3
Offset: 0

Views

Author

Antti Karttunen, Apr 04 2000

Keywords

Comments

Also number of displacements for permutations in lexicographic order. - Joerg Arndt, Jan 22 2024

Crossrefs

Programs

  • Maple
    A055093(n) = count_nonfixed(convert(PermRevLexUnrank(j), 'disjcyc')).
    count_nonfixed := l -> convert(map(nops,l), `+`);
    # Procedure PermRevLexUnrank given in A055089.

Formula

a(n) = A055090(n) + A055091(n).
a(n) = A275812(A290095(n)) = A060129(A060126(n)). - Antti Karttunen, Dec 30 2017

Extensions

Entry revised by Antti Karttunen, Dec 30 2017

A060127 Positions of permutations of A055089 in the permutation sequence A060118. Inverse permutation to A060120.

Original entry on oeis.org

0, 1, 2, 5, 3, 4, 6, 7, 14, 23, 15, 22, 8, 11, 12, 19, 16, 21, 9, 10, 13, 18, 17, 20, 24, 25, 26, 29, 27, 28, 54, 55, 86, 119, 87, 118, 56, 59, 84, 115, 88, 117, 57, 58, 85, 114, 89, 116, 30, 31, 38, 47, 39, 46, 48, 49, 74, 101, 75, 100, 60, 67, 80, 107, 93, 112, 61, 66
Offset: 0

Views

Author

Antti Karttunen, Mar 02 2001

Keywords

Crossrefs

Formula

a(n) = PermRank3L(PermRevLexUnrank(n))

A064640 Positions of non-crossing fixed-point-free involutions (encoded by A014486) in A055089, sorted to ascending order.

Original entry on oeis.org

0, 1, 7, 23, 127, 143, 415, 659, 719, 5167, 5183, 5455, 5699, 5759, 16687, 16703, 26815, 28495, 36899, 36959, 38579, 40031, 40319, 368047, 368063, 368335, 368579, 368639, 379567, 379583, 389695, 391375, 399779, 399839, 401459, 402911, 403199
Offset: 0

Views

Author

Antti Karttunen, Oct 02 2001

Keywords

Comments

These permutations belong to the interpretation (kk) of the exercise 19 in the sixth chapter "Exercises on Catalan and Related Numbers" of Enumerative Combinatorics, Vol. 2, 1999 by R. P. Stanley, Wadsworth, Vol. 1, 1986: Fixed-point-free involutions w of [2n] such that if i < j < k < l and w(i) = k, then w(j) <> l.
From this, it follows that when they are subjected to the same automorphism as used in A061417 and A064636, one gets A002995.

Examples

			The first eight such permutations (after the identity) are in positions 1, 7, 23, 127, 143, 415, 659, 719 of A055089: 21, 2143, 4321, 214365, 432165, 216543, 632541, 654321 which written as disjoint cycles are (1 2), (1 2)(3 4), (1 4)(2 3), (1 2)(3 4)(5 6), (1 4)(2 3)(5 6), (1 2)(3 6)(4 5), (1 6)(2 3)(4 5), (1 6)(2 5)(3 4).
		

Crossrefs

For the needed Maple procedures see A064638. Cf. also A064639, A060112.

Programs

A065181 Permutation of nonnegative integers produced when the finite permutations listed by A055089 are subjected to inverse of Foata's transformation. Inverse of A065182.

Original entry on oeis.org

0, 1, 2, 5, 3, 4, 6, 7, 14, 23, 17, 20, 8, 11, 12, 22, 13, 21, 9, 10, 16, 18, 15, 19, 24, 25, 26, 29, 27, 28, 54, 55, 86, 119, 95, 110, 62, 71, 78, 116, 79, 113, 65, 68, 92, 102, 89, 103, 30, 31, 38, 47, 41, 44, 48, 49, 84, 118, 94, 108, 50, 53, 80, 117, 83, 109, 51, 52
Offset: 0

Views

Author

Antti Karttunen, Oct 19 2001

Keywords

Comments

Here we use the inverse of the left-right maxima variant of Foata's transformation, which works by rotating each cycle largest element first and then sorts the cycles to ascending order, according to that first (and largest) element of each.

References

  • I.M. Gessel and R. P. Stanley, Algebraic Enumeration, chapter 21 in Handbook of Combinatorics, Vol. 2, edited by R.L.Graham et al., The MIT Press, Mass, 1995, page 1045.

Crossrefs

A065161-A065163 give cycle counts and max lengths. Cf. also A065183, A065184 and A055089 and A056019 for the requisite Maple procedures.

Programs

  • Maple
    [seq(PermRevLexRank(FoataInv(PermRevLexUnrank(j))),j=0..119)];
    with(group); FoataInv := p -> map(op, sort([op(map(RotCycleLargestFirst,convert(p,`disjcyc`))),op(FixedCycles(p))], sortbyfirst));
    sortbyfirst := (a,b) -> `if`((a[1] < b[1]),true,false);
    FindLargest := proc(a) local i,m; m := 0; for i from 1 to nops(a) do if(0 = m) then m := i; else if(a[i] > a[m]) then m := i; fi; fi; od; RETURN(m); end;
    RotCycleLargestFirst := proc(c) local x; x := FindLargest(c); if(x <= 1) then RETURN(c); else RETURN([op(c[x..nops(c)]),op(c[1..(x-1)])]); fi; end;
    FixedCycles := proc(p) local a,i; a := []; for i from 1 to nops(p) do if(p[i] = i) then a := [op(a),[i]]; fi; od; RETURN(a); end;

A261096 A(i,j) = rank (in A055089) of the composition of the i-th and the j-th permutation in table A055089, which lists all finite permutations in reversed colexicographic ordering.

Original entry on oeis.org

0, 1, 1, 2, 0, 2, 3, 4, 3, 3, 4, 5, 0, 2, 4, 5, 2, 1, 5, 5, 5, 6, 3, 5, 4, 1, 4, 6, 7, 7, 4, 0, 0, 3, 7, 7, 8, 6, 12, 1, 3, 2, 8, 6, 8, 9, 10, 13, 13, 2, 1, 9, 10, 9, 9, 10, 11, 14, 12, 18, 0, 10, 11, 6, 8, 10, 11, 8, 15, 16, 19, 19, 11, 8, 7, 11, 11, 11, 12, 9, 16, 17, 20, 18, 0, 9, 11, 10, 7, 10, 12, 13, 18, 17, 14, 21, 22, 1, 1, 10, 6, 6, 9, 13, 13, 14, 19, 6, 15, 22, 23, 2, 0, 14, 7, 9, 8, 14, 12, 14
Offset: 0

Views

Author

Antti Karttunen, Aug 26 2015

Keywords

Comments

The square array A(row>=0, col>=0) is read by downwards antidiagonals as: A(0,0), A(0,1), A(1,0), A(0,2), A(1,1), A(2,0), A(0,3), A(1,2), A(2,1), A(3,0), ...
A(i,j) gives the rank (in ordering used by table A055089) of the permutation which is obtained by composing permutations p and q listed as the i-th and the j-th permutation in irregular table A055089 (note that the identity permutation is the 0th). Here the convention is that "permutations act of the left", thus, if p1 and p2 are permutations, then the product of p1 and p2 (p1 * p2) is defined such that (p1 * p2)(i) = p1(p2(i)) for i=1...
Each row and column is a permutation of A001477, because this is the Cayley table ("multiplication table") of an infinite enumerable group, namely, that subgroup of the infinite symmetric group (S_inf) which consists of permutations moving only finite number of elements.

Examples

			The top left corner of the array:
   0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, ...
   1,  0,  4,  5,  2,  3,  7,  6, 10, 11,  8,  9, 18, ...
   2,  3,  0,  1,  5,  4, 12, 13, 14, 15, 16, 17,  6, ...
   3,  2,  5,  4,  0,  1, 13, 12, 16, 17, 14, 15, 19, ...
   4,  5,  1,  0,  3,  2, 18, 19, 20, 21, 22, 23,  7, ...
   5,  4,  3,  2,  1,  0, 19, 18, 22, 23, 20, 21, 13, ...
   6,  7,  8,  9, 10, 11,  0,  1,  2,  3,  4,  5, 14, ...
   7,  6, 10, 11,  8,  9,  1,  0,  4,  5,  2,  3, 20, ...
   8,  9,  6,  7, 11, 10, 14, 15, 12, 13, 17, 16,  0, ...
   9,  8, 11, 10,  6,  7, 15, 14, 17, 16, 12, 13, 21, ...
  10, 11,  7,  6,  9,  8, 20, 21, 18, 19, 23, 22,  1, ...
  11, 10,  9,  8,  7,  6, 21, 20, 23, 22, 18, 19, 15, ...
  12, 13, 14, 15, 16, 17,  2,  3,  0,  1,  5,  4,  8, ...
  ...
For A(1,2) (row=1, column=2, both starting from zero), we take as permutation p the permutation which has rank=1 in the ordering used by A055089, which is a simple transposition (1 2), which we can extend with fixed terms as far as we wish (e.g., like {2,1,3,4,5,...}), and as permutation q we take the permutation which has rank=2 (in the same list), which is {1,3,2}. We compose these from the left, so that the latter one, q, acts first, thus c(i) = p(q(i)), and the result is permutation {2,3,1}, which is listed as the 4th one in A055089, thus A(1,2) = 4.
For A(2,1) we compose those two permutations in opposite order, as d(i) = q(p(i)), which gives permutation {3,1,2} which is listed as the 3rd one in A055089, thus A(2,1) = 3.
		

Crossrefs

Transpose: A261097.
Row 0 & Column 0: A001477 (identity permutation).
Row 1: A261098.
Column 1: A004442.
Main diagonal: A261099.
Cf. tables A055089, A195663.
Cf. also A261216, A261217 (similar arrays, but using different orderings of permutations).
Permutations used in conjugation-formulas: A056019, A060119, A060120, A060126, A060127.

Formula

By conjugating with related permutations and arrays:
A(i,j) = A056019(A261097(A056019(i),A056019(j))).
A(i,j) = A060119(A261216(A060126(i),A060126(j))).
A(i,j) = A060120(A261217(A060127(i),A060127(j))).
Showing 1-10 of 70 results. Next