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.

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A074759 Number of degree-n permutations of order dividing n. Number of solutions to x^n = 1 in S_n.

Original entry on oeis.org

1, 1, 2, 3, 16, 25, 396, 721, 11264, 46089, 602200, 3628801, 133494912, 479001601, 7692266960, 95904273375, 1914926104576, 20922789888001, 628693317946656, 6402373705728001, 182635841123840000, 2496321046987530021, 55826951075231672512, 1124000727777607680001
Offset: 0

Views

Author

Vladeta Jovovic, Sep 28 2002

Keywords

Crossrefs

Main diagonal of A008307.

Programs

  • Maple
    A:= proc(n,k) option remember; `if`(n<0, 0, `if`(n=0, 1,
           add(mul(n-i, i=1..j-1)*A(n-j,k), j=numtheory[divisors](k))))
        end:
    a:= n-> A(n, n):
    seq(a(n), n=0..25);  # Alois P. Heinz, Feb 14 2013
  • Mathematica
    Table[a = Sum[x^i/i, {i, Divisors[n]}]; Part[Range[0, 20]! CoefficientList[Series[Exp[a], {x, 0, 20}], x],n + 1], {n, 0, 20}]  (* Geoffrey Critzer, Dec 04 2011 *)

Formula

a(n) = n! * [x^n] exp(Sum_{k divides n} x^k/k).
a(n) = Sum_{d|n} A057731(n,d) for n >= 1. - Alois P. Heinz, Jul 05 2021

A171806 Number of 5 X 5 permutation matrices such that the n-th matrix power is the least nonnegative power that gives the identity matrix.

Original entry on oeis.org

1, 25, 20, 30, 24, 20
Offset: 1

Views

Author

Artur Jasinski, Dec 18 2009

Keywords

Comments

The sum of the terms of this sequence is equal to the number of 5 X 5 permutation matrices: 5! = 120.
Number of elements of order n in symmetric group S_5. - Alois P. Heinz, Mar 30 2020

Examples

			a(1) = 1 because there is only one matrix whose first power is the identity matrix (this is the identity matrix itself).
		

Crossrefs

Row n=5 of A057731.

Programs

  • Mathematica
    tab = {0, 0, 0, 0, 0, 0}; per =
     Permutations[{1, 2, 3, 4, 5}]; zeromat = {}; Do[
     AppendTo[zeromat, Table[0, {n, 1, 5}]], {m, 1, 5}]; unit =
     IdentityMatrix[5]; s5 = {}; Do[s = zeromat;
     Do[s[[m]][[per[[n]][[m]]]] = 1, {m, 1, 5}];
     AppendTo[s5, s], {n, 1, 120}]; Do[
     If[MatrixPower[s5[[n]], 1] == unit, tab[[1]] = tab[[1]] + 1,
      If[MatrixPower[s5[[n]], 2] == unit, tab[[2]] = tab[[2]] + 1,
       If[MatrixPower[s5[[n]], 3] == unit, tab[[3]] = tab[[3]] + 1,
        If[MatrixPower[s5[[n]], 4] == unit, tab[[4]] = tab[[4]] + 1,
         If[MatrixPower[s5[[n]], 5] == unit, tab[[5]] = tab[[5]] + 1,
          If[MatrixPower[s5[[n]], 6] == unit,
           tab[[6]] = tab[[6]] + 1]]]]]], {n, 1, 120}]; tab

Extensions

Name edited and terms corrected by Alois P. Heinz, Mar 30 2020

A346085 Number T(n,k) of permutations of [n] such that k is the GCD of the cycle lengths; triangle T(n,k), n>=0, 0<=k<=n, read by rows.

Original entry on oeis.org

1, 0, 1, 0, 1, 1, 0, 4, 0, 2, 0, 15, 3, 0, 6, 0, 96, 0, 0, 0, 24, 0, 455, 105, 40, 0, 0, 120, 0, 4320, 0, 0, 0, 0, 0, 720, 0, 29295, 4725, 0, 1260, 0, 0, 0, 5040, 0, 300160, 0, 22400, 0, 0, 0, 0, 0, 40320, 0, 2663199, 530145, 0, 0, 72576, 0, 0, 0, 0, 362880
Offset: 0

Views

Author

Alois P. Heinz, Jul 04 2021

Keywords

Examples

			T(3,1) = 4: (1)(23), (13)(2), (12)(3), (1)(2)(3).
T(4,4) = 6: (1234), (1243), (1324), (1342), (1423), (1432).
Triangle T(n,k) begins:
  1;
  0,       1;
  0,       1,      1;
  0,       4,      0,     2;
  0,      15,      3,     0,    6;
  0,      96,      0,     0,    0,    24;
  0,     455,    105,    40,    0,     0, 120;
  0,    4320,      0,     0,    0,     0,   0, 720;
  0,   29295,   4725,     0, 1260,     0,   0,   0, 5040;
  0,  300160,      0, 22400,    0,     0,   0,   0,    0, 40320;
  0, 2663199, 530145,     0,    0, 72576,   0,   0,    0,     0, 362880;
  ...
		

Crossrefs

Columns k=0-1 give: A000007, A079128.
Even bisection of column k=2 gives A346086.
Row sums give A000142.
T(2n,n) gives A110468(n-1) for n >= 1.

Programs

  • Maple
    b:= proc(n, g) option remember; `if`(n=0, x^g, add((j-1)!
          *b(n-j, igcd(g, j))*binomial(n-1, j-1), j=1..n))
        end:
    T:= n-> (p-> seq(coeff(p, x, i), i=0..n))(b(n, 0)):
    seq(T(n), n=0..12);
  • Mathematica
    b[n_, g_] := b[n, g] = If[n == 0, x^g, Sum[(j - 1)!*
         b[n - j, GCD[g, j]] Binomial[n - 1, j - 1], {j, n}]];
    T[n_] := CoefficientList[b[n, 0], x];
    Table[T[n], {n, 0, 12}] // Flatten (* Jean-François Alcover, Aug 30 2021, after Alois P. Heinz *)

Formula

Sum_{k=1..n} k * T(n,k) = A346066(n).
Sum_{prime p <= n} T(n,p) = A359951(n). - Alois P. Heinz, Jan 20 2023

A074881 Triangle T(n,k) giving number of labeled cyclic subgroups of order k in symmetric group S_n, n >= 1, 1 <= k <= g(n), where g(n) = A000793(n) is Landau's function.

Original entry on oeis.org

1, 1, 1, 1, 3, 1, 1, 9, 4, 3, 1, 25, 10, 15, 6, 10, 1, 75, 40, 90, 36, 120, 1, 231, 175, 420, 126, 735, 120, 126, 105, 1, 763, 616, 2730, 336, 5320, 960, 1260, 1008, 840, 336, 1, 2619, 2884, 15498, 756, 41580, 4320, 11340, 6720, 6804, 7560, 4320, 3024, 2268
Offset: 1

Views

Author

Vladeta Jovovic, Sep 30 2002

Keywords

Comments

A057731 contains zeros. This sequence contains only positive values of A057731(n,k)/A000010(k). - Alois P. Heinz, Feb 16 2013

Examples

			Triangle begins:
  1;
  1,   1;
  1,   3,   1;
  1,   9,   4,   3;
  1,  25,  10,  15,   6,  10;
  1,  75,  40,  90,  36, 120;
  1, 231, 175, 420, 126, 735, 120, 126, 105;
  ...
		

Crossrefs

Row sums give A051625.

Programs

  • Mathematica
    nmax = 10;
    T[n_, k_] := n! SeriesCoefficient[O[x]^(n+1) + Sum[MoebiusMu[k/i]*Exp[ Sum[x^j/j, {j, Divisors[i]}]], {i, Divisors[k]}], {x, 0, n}]/ EulerPhi[k];
    Table[DeleteCases[Table[T[n, k], {k, 1, 2 nmax}], 0], {n, 1, nmax}] // Flatten (* Jean-François Alcover, Sep 16 2019, after Andrew Howroyd *)
  • PARI
    T(n,k)={n!*polcoeff(sumdiv(k, i, moebius(k/i)*exp(sumdiv(i, j, x^j/j) + O(x*x^n))), n)/eulerphi(k)} \\ Andrew Howroyd, Jul 02 2018

Formula

T(n,k) = A057731(n,k)/A000010(k).

A153760 Number of degree-n permutations of order exactly 7.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 720, 5760, 25920, 86400, 237600, 570240, 1235520, 892045440, 13348249200, 106757164800, 604924594560, 2722120577280, 10344007402560, 34479959558400, 24928970490633600, 546446134633639680, 6281586217487489040, 50248618811434961280
Offset: 1

Views

Author

Franz Vrabec, Jan 01 2009

Keywords

Crossrefs

Column k=7 of A057731. - Alois P. Heinz, Feb 16 2013

Programs

  • Maple
    a:= proc(n) option remember;
          `if`(n<7, 0, a(n-1)+(1+a(n-7))*(n-1)!/(n-7)!)
        end:
    seq(a(n), n=1..30);  # Alois P. Heinz, Feb 16 2013
  • Mathematica
    Rest[CoefficientList[Series[-Exp[x] + Exp[x + 1/7*x^7], {x, 0, 25}], x]*Range[0, 25]!] (* G. C. Greubel, Aug 27 2016 *)
  • PARI
    seq(n)={Vec(serlaplace(-exp(x + O(x*x^n)) + exp(x + x^7/7 + O(x*x^n))),-n)} \\ Andrew Howroyd, Jul 02 2018

Formula

E.g.f.: -exp(x)+exp(x+1/7*x^7). - Alois P. Heinz, Feb 16 2013

Extensions

More terms from Alois P. Heinz, Feb 16 2013

A214003 Number of degree-n permutations of prime order.

Original entry on oeis.org

0, 1, 5, 17, 69, 299, 1805, 9099, 37331, 205559, 4853529, 49841615, 789513659, 9021065871, 70737031469, 420565124399, 22959075244095, 385032305178719, 10010973102879761, 152163983393187399, 1498273284120348539, 15639918041915598815, 1296204202723400597109
Offset: 1

Views

Author

Stephen A. Silver, Feb 15 2013

Keywords

Examples

			The symmetric group S_5 has 25 elements of order 2, 20 elements of order 3, and 24 elements of order 5. All other elements are of nonprime order (1, 4, or 6), so a(5) = 25 + 20 + 24 = 69.
		

Crossrefs

Programs

  • Maple
    b:= proc(n,p) option remember;
          `if`(n add(b(n, ithprime(i)), i=1..numtheory[pi](n)):
    seq(a(n), n=1..30);  # Alois P. Heinz, Feb 16 2013
    # second Maple program:
    b:= proc(n, g) option remember; `if`(n=0, `if`(isprime(g), 1, 0),
          add(b(n-j, ilcm(j, g))*(n-1)!/(n-j)!, j=1..n))
        end:
    a:= n-> b(n, 1):
    seq(a(n), n=1..23);  # Alois P. Heinz, Jan 19 2023
  • Mathematica
    f[list_] :=Total[list]!/Apply[Times, list]/Apply[Times, Map[Length, Split[list]]!]; Table[Total[Map[f, Select[Partitions[n],PrimeQ[Apply[LCM, #]] &]]], {n, 1,23}] (* Geoffrey Critzer, Nov 08 2015 *)

Formula

a(n) = Sum_{p prime} A057731(n,p).
E.g.f.: exp(x)*Sum_{p in Primes} exp(x^p/p)-1. - Geoffrey Critzer, Nov 08 2015

A153761 Number of degree-n permutations of order exactly 11.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3628800, 43545600, 283046400, 1320883200, 4953312000, 15850598400, 44910028800, 115482931200, 274271961600, 609493248000, 1279935820800, 4644633666390681600, 106826520356358566400, 1281918194457262387200, 10682651561168805120000
Offset: 1

Views

Author

Franz Vrabec, Jan 01 2009

Keywords

Crossrefs

Column k=11 of A057731. - Alois P. Heinz, Feb 16 2013

Programs

  • Maple
    a:= proc(n) option remember;
          `if`(n<11, 0, a(n-1)+(1+a(n-11))*(n-1)!/(n-11)!)
        end:
    seq(a(n), n=1..30);  # Alois P. Heinz, Feb 16 2013
  • Mathematica
    Rest[CoefficientList[Series[-Exp[x] + Exp[x + 1/11*x^11], {x, 0, 25}], x]*Range[0, 25]!] (* G. C. Greubel, Aug 27 2016 *)

Formula

E.g.f.: -exp(x)+exp(x+1/11*x^11). - Alois P. Heinz, Feb 16 2013

Extensions

More terms from Alois P. Heinz, Feb 16 2013

A057741 Table T(n,k) giving number of elements of order k in dihedral group D_{2n} of order 2n, n >= 1, 1<=k<=g(n), where g(n) = 2 if n=1 else g(n) = n.

Original entry on oeis.org

1, 1, 1, 3, 1, 3, 2, 1, 5, 0, 2, 1, 5, 0, 0, 4, 1, 7, 2, 0, 0, 2, 1, 7, 0, 0, 0, 0, 6, 1, 9, 0, 2, 0, 0, 0, 4, 1, 9, 2, 0, 0, 0, 0, 0, 6, 1, 11, 0, 0, 4, 0, 0, 0, 0, 4, 1, 11, 0, 0, 0, 0, 0, 0, 0, 0, 10, 1, 13, 2, 2, 0, 2, 0, 0, 0, 0, 0, 4, 1, 13, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12, 1, 15, 0, 0, 0, 0, 6, 0, 0
Offset: 1

Views

Author

Roger Cuculière, Oct 29 2000

Keywords

Comments

Note that D_2 equals the cyclic group of order 2.

Examples

			1,1;
1,3;
1,3,2;
1,5,0,2;
1,5,0,0,4; ...
		

Crossrefs

Programs

  • Mathematica
    t[n_, k_] /; k != 2 && ! Divisible[n, k] = 0; t[n_, k_] /; k != 2 && Divisible[n, k] := EulerPhi[k]; t[n_, 2] := n + 1 - Mod[n, 2]; Flatten[Table[t[n, k], {n, 1, 14}, {k, 1, If[n == 1, 2, n]}]] (* Jean-François Alcover, Jun 19 2012, from formula *)
    row[n_] := (orders = PermutationOrder /@ GroupElements[DihedralGroup[n]]; Table[Count[orders, k], {k, 1, Max[orders]}]); Table[row[n], {n, 1, 14}] // Flatten (* Jean-François Alcover, Aug 31 2016 *)

Formula

If k<>2 and k does not divide n, this number is 0; if k<>2 and k divides n, this number is phi(k), where phi is the Euler totient function; if k=2, this number is n for odd n and n+1 for even n.

Extensions

More terms from James Sellers, Oct 30 2000

A339122 Number of elements of the Rubik's Cube group of order A338883(n).

Original entry on oeis.org

1, 170911549183, 33894540622394, 4346957030144256, 133528172514624, 140621059298755526, 153245517148800, 294998638981939200, 55333752398428896, 34178553690432192, 44590694400, 2330232827455554048, 23298374383021440, 14385471333209856, 150731886270873600
Offset: 1

Views

Author

Ben Whitmore, Nov 24 2020

Keywords

Comments

The most common order is 60, with a(33) = 4199961633799421952 elements, or about 9.71% of the group.
The least common order (excluding 1) is 11, with a(11) = 44590694400 elements, or about 0.0000001% of the group. Elements of order 11 are rare because they cannot affect the corner pieces of the cube.

Examples

			a(1) = 1 because the only element of order A338883(1) = 1 is the identity element.
a(73) = 51490480088678400 is the number of elements of order A338883(73) = 1260.
		

Crossrefs

Programs

  • Mathematica
    pN[p_] := Total[p]!/Times@@p/Times@@Factorial[Flatten[Tally[p]][[2 ;; ;; 2]]]
    oddQ[p_] := OddQ[Total[p - 1]]
    ord[p_] := LCM @@ p
    oriN[p_, o_] := Module[{i, t, a = 0, ns = 0, s = 0, r}, t = ord[p]/p;
      For[i = 1, i <= Length[p], i++,
       If[Mod[t[[i]], o] == 0, a += p[[i]], ns += 1; s += p[[i]]]];
         {If[a == 0, r = o^(s - ns), r = o^a o^(s - ns - 1)], o^(a + s - 1) - r}]
    val[p1_, o1_, p2_, o2_] :=
    Module[{z}, z = pN[p1] pN[p2];
         {{LCM[ord[p1], ord[p2]],z oriN[p1, o1][[1]] oriN[p2, o2][[1]]},
         {{LCM[ord[p1] o1,ord[p2]],z oriN[p1, o1][[2]] oriN[p2, o2][[1]]}},   {{LCM[ord[p1],ord[p2] o2],z oriN[p1, o1][[1]] oriN[p2, o2][[2]]}},
      {{LCM[ord[p1] o1, ord[p2] o2], z oriN[p1, o1][[2]] oriN[p2, o2][[2]] }}}]
    p8 = IntegerPartitions[8]; p12 = IntegerPartitions[12];
    ce = Select[p8, ! oddQ[#] &]; co = Select[p8, oddQ[#] &];
    ee = Select[p12, ! oddQ[#] &]; eo = Select[p12, oddQ[#] &];
    res = {}; max = 0;
    For[i = 1, i <= Length[ce], i++,
    For[j = 1, j <= Length[ee], j++,
      AppendTo[res, val[ce[[i]], 3, ee[[j]], 2]]]]
    For[i = 1, i <= Length[co], i++,
    For[j = 1, j <= Length[eo], j++,
      AppendTo[res, val[co[[i]], 3, eo[[j]], 2]]]]
    p = Partition[res // Flatten, 2]; c // Clear;
    For[i = 1, i <= Length[p], i++,
      If [IntegerQ[c[p[[i, 1]]]], c[p[[i, 1]]] += p[[i, 2]],
       c[p[[i, 1]]] = p[[i, 2]]]; If[p[[i, 1]] > max, max = p[[i, 1]]]];
    Select[Table[c[i], {i, 1, max}], IntegerQ[#] &] (* Herbert Kociemba, Jun 30 2022 *)
  • Python
    # See post #11 in SpeedSolving Puzzles Community link.

Formula

Sum_{n=1..73} a(n) = 43252003274489856000 = A075152(3).

Extensions

a(10) corrected by Ben Whitmore, Jun 27 2022

A345628 Irregular triangle T(n,k) read by rows of the number of elements of order k in the dicyclic group Dic(n) for n>=2.

Original entry on oeis.org

1, 1, 0, 6, 1, 1, 2, 6, 0, 2, 1, 1, 0, 10, 0, 0, 0, 4, 1, 1, 0, 10, 4, 0, 0, 0, 0, 4, 1, 1, 2, 14, 0, 2, 0, 0, 0, 0, 0, 4, 1, 1, 0, 14, 0, 0, 6, 0, 0, 0, 0, 0, 0, 6, 1, 1, 0, 18, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 8, 1, 1, 2, 18, 0, 2, 0, 0, 6, 0, 0, 0, 0, 0, 0
Offset: 2

Views

Author

Sean A. Irvine, Jun 22 2021

Keywords

Comments

Dic(1) is omitted since it is degenerate.
Row n has 2*n entries (k=1..2*n).

Examples

			Triangle begins:
  1, 1, 0,  6;
  1, 1, 2,  6, 0, 2;
  1, 1, 0,  1, 0, 0, 0, 4;
  1, 1, 0, 10, 4, 0, 0, 0, 0, 4;
  ...
		

Crossrefs

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