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 18 results. Next

A290095 a(n) = A275725(A060126(n)); prime factorization encodings of cycle-polynomials computed for finite permutations listed in reversed colexicographic ordering.

Original entry on oeis.org

2, 4, 18, 8, 8, 12, 150, 100, 54, 16, 16, 24, 54, 16, 90, 40, 36, 16, 16, 24, 40, 60, 16, 36, 1470, 980, 882, 392, 392, 588, 750, 500, 162, 32, 32, 48, 162, 32, 270, 80, 108, 32, 32, 48, 80, 120, 32, 72, 750, 500, 162, 32, 32, 48, 1050, 700, 378, 112, 112, 168, 450, 200, 162, 32, 32, 72, 200, 300, 32, 48, 108, 32, 162, 32, 270, 80, 108, 32, 378, 112, 630, 280
Offset: 0

Views

Author

Antti Karttunen, Aug 17 2017

Keywords

Comments

In this context "cycle-polynomials" are single-variable polynomials where the coefficients (encoded with the exponents of prime factorization of n) are equal to the lengths of cycles in the permutation listed with index n in table A055089 (A195663). See the examples.

Examples

			Consider the first eight permutations (indices 0-7) listed in A055089:
  1 [Only the first 1-cycle explicitly listed thus a(0) = 2^1 = 2]
  2,1 [One transposition (2-cycle) in beginning, thus a(1) = 2^2 = 4]
  1,3,2 [One fixed element in beginning, then transposition, thus a(2) = 2^1 * 3^2 = 18]
  3,1,2 [One 3-cycle, thus a(3) = 2^3 = 8]
  2,3,1 [One 3-cycle, thus a(4) = 2^3 = 8]
  3,2,1 [One transposition jumping over a fixed element, a(5) = 2^2 * 3^1 = 12]
  1,2,4,3 [Two 1-cycles, then a 2-cycle, thus a(6) = 2^1 * 3^1 * 5^2 = 150].
  2,1,4,3 [Two 2-cycles, not crossed, thus a(7) = 2^2 * 5^2 = 100].
		

Crossrefs

Formula

a(n) = A275725(A060126(n)).
Other identities:
A046523(a(n)) = A290096(n).
A056170(a(n)) = A055090(n).
A046660(a(n)) = A055091(n).
A072411(a(n)) = A055092(n).
A275812(a(n)) = A055093(n).

A060132 Positions of the permutations which have the same rank in A055089 and A060117, i.e., the fixed points of permutations A060119 and A060126.

Original entry on oeis.org

0, 1, 2, 3, 6, 7, 8, 9, 16, 17, 24, 25, 26, 27, 30, 31, 32, 33, 40, 41, 60, 61, 62, 63, 120, 121, 122, 123, 126, 127, 128, 129, 136, 137, 144, 145, 146, 147, 150, 151, 152, 153, 160, 161, 180, 181, 182, 183, 288, 289, 290, 291, 294, 295, 296, 297, 304, 305, 316
Offset: 0

Views

Author

Antti Karttunen, Mar 02 2001

Keywords

Crossrefs

Cf. A060133. Includes A059590 as a subset and A064637 gives the terms that are not found therein.

Programs

  • Maple
    sub1 := n -> (n - 1); map(sub1,positions(0,[seq(PermRank3R(PermRevLexUnrank(n))-n,n=0..1024)])); or map(sub1,positions(0,[seq(PermRevLexRank(PermUnrank3R(n))-n,n=0..1024)]));

A060125 Self-inverse infinite permutation which shows the position of the inverse of each finite permutation in A060117 (or A060118) in the same sequence; or equally, the cross-indexing between A060117 and A060118.

Original entry on oeis.org

0, 1, 2, 5, 4, 3, 6, 7, 14, 23, 22, 15, 12, 19, 8, 11, 16, 21, 18, 13, 20, 17, 10, 9, 24, 25, 26, 29, 28, 27, 54, 55, 86, 119, 118, 87, 84, 115, 56, 59, 88, 117, 114, 85, 116, 89, 58, 57, 48, 49, 74, 101, 100, 75, 30, 31, 38, 47, 46, 39, 60, 67, 80, 107, 112, 93, 66, 61, 92
Offset: 0

Views

Author

Antti Karttunen, Mar 02 2001

Keywords

Comments

PermRank3Aux is a slight modification of rank2 algorithm presented in Myrvold-Ruskey article.

Crossrefs

Cf. A261220 (fixed points).
Cf. A056019 (compare the scatter plots).

Programs

  • Maple
    with(group); permul := (a,b) -> mulperms(b,a); swap := (p,i,j) -> convert(permul(convert(p,'disjcyc'),[[i,j]]),'permlist',nops(p));
    PermRank3Aux := proc(n, p, q) if(1 = n) then RETURN(0); else RETURN((n-p[n])*((n-1)!) + PermRank3Aux(n-1,swap(p,n,q[n]),swap(q,n,p[n]))); fi; end;
    PermRank3R := p -> PermRank3Aux(nops(p),p,convert(invperm(convert(p,'disjcyc')),'permlist',nops(p)));
    PermRank3L := p -> PermRank3Aux(nops(p),convert(invperm(convert(p,'disjcyc')),'permlist',nops(p)),p);
    # a(n) = PermRank3L(PermUnrank3R(n)) or PermRank3R(PermUnrank3L(n)) or PermRank3L(convert(invperm(convert(PermUnrank3L(j), 'disjcyc')), 'permlist', nops(PermUnrank3L(j))))

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

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))

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))).

A261216 A(i,j) = rank (in A060117) of the composition of the i-th and the j-th permutation in table A060117, which lists all finite permutations.

Original entry on oeis.org

0, 1, 1, 2, 0, 2, 3, 5, 3, 3, 4, 4, 0, 2, 4, 5, 3, 1, 4, 5, 5, 6, 2, 5, 5, 3, 4, 6, 7, 7, 4, 1, 2, 1, 7, 7, 8, 6, 14, 0, 0, 0, 8, 6, 8, 9, 11, 15, 15, 1, 2, 9, 11, 9, 9, 10, 10, 12, 14, 22, 3, 10, 10, 6, 8, 10, 11, 9, 13, 16, 23, 23, 11, 9, 7, 10, 11, 11, 12, 8, 17, 17, 21, 22, 0, 8, 11, 11, 9, 10, 12, 13, 19, 16, 13, 20, 19, 1, 1, 10, 7, 8, 7, 13, 13, 14, 18, 8, 12, 18, 18, 2, 0, 12, 6, 6, 6, 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 of the permutation (in ordering used by table A060117) which is obtained by composing permutations p and q listed as the i-th and the j-th permutation in irregular table A060117 (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...
Equally, A(i,j) gives the rank in A060118 of the composition of the i-th and the j-th permutation in A060118, when convention is that "permutations act on the right".
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,  5,  4,  3,  2,  7,  6, 11, 10,  9,  8, 19, ...
   2,  3,  0,  1,  5,  4, 14, 15, 12, 13, 17, 16,  8, ...
   3,  2,  4,  5,  1,  0, 15, 14, 16, 17, 13, 12, 21, ...
   4,  5,  3,  2,  0,  1, 22, 23, 21, 20, 18, 19, 16, ...
   5,  4,  1,  0,  2,  3, 23, 22, 19, 18, 20, 21, 11, ...
   6,  7,  8,  9, 10, 11,  0,  1,  2,  3,  4,  5, 14, ...
   7,  6, 11, 10,  9,  8,  1,  0,  5,  4,  3,  2, 23, ...
   8,  9,  6,  7, 11, 10, 12, 13, 14, 15, 16, 17,  2, ...
   9,  8, 10, 11,  7,  6, 13, 12, 17, 16, 15, 14, 20, ...
  10, 11,  9,  8,  6,  7, 18, 19, 20, 21, 22, 23, 17, ...
  11, 10,  7,  6,  8,  9, 19, 18, 23, 22, 21, 20,  5, ...
  12, 13, 14, 15, 16, 17,  8,  9,  6,  7, 11, 10,  0, ...
  ...
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 A060117, 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 5th one in A060117, thus A(1,2) = 5.
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 A060117, thus A(2,1) = 3.
		

Crossrefs

Transpose: A261217.
Row 0 & Column 0: A001477 (identity permutation).
Row 1: A261218.
Column 1: A004442.
Main diagonal: A261219.
Permutations used in conjugation-formulas: A060119, A060120, A060125, A060126, A060127.

Formula

By conjugating with related permutations and arrays:
A(i,j) = A060125(A261217(A060125(i),A060125(j))).
A(i,j) = A060126(A261096(A060119(i),A060119(j))).
A(i,j) = A060127(A261097(A060120(i),A060120(j))).

A055092 Order of each permutation given in reversed colexicographic ordering A055089, i.e., the least common multiple of their cycle lengths.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Apr 04 2000

Keywords

Crossrefs

Programs

  • Maple
    A055092(n) = count_permorder(convert(PermRevLexUnrank(j), 'disjcyc')).
    count_permorder := proc(l) local c,t; t := 1; for c in l do t := ilcm(t,nops(c)); od; RETURN(t); end;
    # Procedure PermRevLexUnrank given in A055089.

Formula

a(n) = A072411(A290095(n)) = A060131(A060126(n)). - Antti Karttunen, Dec 30 2017

Extensions

Entry revised by Antti Karttunen, Dec 30 2017
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