A001473 -id:A001473 - cp's OEIS frontend

A001189 Number of degree-n permutations of order exactly 2.

0, 1, 3, 9, 25, 75, 231, 763, 2619, 9495, 35695, 140151, 568503, 2390479, 10349535, 46206735, 211799311, 997313823, 4809701439, 23758664095, 119952692895, 618884638911, 3257843882623, 17492190577599, 95680443760575, 532985208200575, 3020676745975551

Offset: 1

N. J. A. Sloane

Number of set partitions of [n] into blocks of size 2 and 1 with at least one block of size 2. - Olivier Gérard, Oct 29 2007

For n>=2, number of standard Young tableaux with height <= n - 1. That is, all tableaux (A000085) but the one with just one column. - Joerg Arndt, Oct 24 2012

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Alois P. Heinz, Table of n, a(n) for n = 1..800
N. Chheda, M. K. Gupta, RNA as a Permutation, arXiv:1403.5477 [q-bio.BM], 2014.
R. B. Herrera, The number of elements of given period in finite symmetric group, Amer. Math. Monthly 64, 1957, 488-490.
L. Moser and M. Wyman, On solutions of x^d = 1 in symmetric groups, Canad. J. Math., 7 (1955), 159-168.
J. Rangel-Mondragon, Selected Themes in Computational Non-Euclidean Geometry: Part 1, The Mathematica Journal 15 (2013); http://www.mathematica-journal.com/data/uploads/2013/07/Rangel-Mondragon_Selected-1.pdf
Martin Svatoš, Peter Jung, Jan Tóth, Yuyi Wang, and Ondřej Kuželka, On Discovering Interesting Combinatorial Integer Sequences, arXiv:2302.04606 [cs.LO], 2023, p. 17.
Thotsaporn Thanatipanonda, Inversions and major index for permutations, Math. Mag., April 2004.

Cf. A001470-A001473, A052501, A053496-A053504, A061121-A061128.
Column k=1 of A143911, column k=2 of A080510, A182222. - Alois P. Heinz, Oct 24 2012
Column k=2 of A057731. - Alois P. Heinz, Feb 14 2013

m:=30; R:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!( Exp(x + x^2/2) -Exp(x) )); [0] cat [Factorial(n+1)*b[n]: n in [1..m-2]]; // G. C. Greubel, May 14 2019

a:= proc(n) option remember; `if`(n<3, [0$2, 1][n+1],
      a(n-1) +(n-1) *(1+a(n-2)))
    end:
seq(a(n), n=1..30);  # Alois P. Heinz, Oct 24 2012
# alternative:
A001189 := proc(n)
    local a,prs,p,k ;
    a := 0 ;
    for prs from 1 to n/2 do
        p := product(binomial(n-2*k,2),k=0..prs-1) ;
        a := a+p/prs!;
    end do:
    a;
end proc:
seq(A001189(n),n=1..13) ; # R. J. Mathar, Jan 04 2017

RecurrenceTable[{a[1]==0,a[2]==1,a[n]==a[n-1]+(1+a[n-2])(n-1)},a[n],{n,25}] (* Harvey P. Dale, Jul 27 2011 *)

{a(n) = sum(j=1,floor(n/2), n!/(j!*(n-2*j)!*2^j))}; \\ G. C. Greubel, May 14 2019

m = 30; T = taylor(exp(x +x^2/2) - exp(x), x, 0, m); a=[factorial(n)*T.coefficient(x, n) for n in (0..m)]; a[1:] # G. C. Greubel, May 14 2019

E.g.f.: exp(x + x^2/2) - exp(x).
a(n) = A000085(n) - 1.
a(n) = b(n, 2), where b(n, d)=Sum_{k=1..n} (n-1)!/(n-k)! * Sum_{l:lcm{k, l}=d} b(n-k, l), b(0, 1)=1 is the number of degree-n permutations of order exactly d.
From Henry Bottomley, May 03 2001: (Start)
a(n) = a(n-1) + (1 + a(n-2))*(n-1).
a(n) = Sum_{j=1..floor(n/2)} n!/(j!*(n-2*j)!*(2^j)). (End)

A001471 Number of degree-n permutations of order exactly 3.

Original entry on oeis.org

0, 0, 0, 2, 8, 20, 80, 350, 1232, 5768, 31040, 142010, 776600, 4874012, 27027728, 168369110, 1191911840, 7678566800, 53474964992, 418199988338, 3044269834280, 23364756531620, 199008751634000, 1605461415071822

Offset: 0

N. J. A. Sloane and J. H. Conway

a(n) is the number of non-symmetric permutation matrices A of dimension n such that A^2 is the transpose of A. - Torlach Rush, Jul 09 2020

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

T. D. Noe, Table of n, a(n) for n = 0..100
L. Moser and M. Wyman, On solutions of x^d = 1 in symmetric groups, Canad. J. Math., 7 (1955), 159-168.

Cf. A000085, A001470, A001472, A052501, A053496-A053505, A001189, A001471, A001473, A061121-A061128.

Column k=3 of A057731.

m:=30; R:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!( Exp(x + x^3/3) )); [Factorial(n-1)*b[n]-1: n in [1..m]]; // G. C. Greubel, May 14 2019

a[n_] := HypergeometricPFQ[{1/3-n/3, 2/3-n/3, -n/3}, {}, -9] - 1; Table[a[n], {n, 0, 23}] (* Jean-François Alcover, Oct 19 2011 *)
nxt[{n_,a_,b_,c_}]:={n+1,b,c,c+(1+a)(n-1)(n-2)}; NestList[nxt,{3,0,0,0},25][[;;,2]] (* Harvey P. Dale, Mar 09 2024 *)

a(n)=sum(j=1,n\3, n!/(j!*(n-3*j)!*(3^j))) \\ Charles R Greathouse IV, Jun 21 2017

first(n)=my(v=vector(n+1)); for(i=3,n, v[i+1]=v[i] + (1+v[i-2])*(i-1)*(i-2)); v \\ Charles R Greathouse IV, Jul 10 2020

m = 30; T = taylor(exp(x + x^3/3) -exp(x), x, 0, m); [factorial(n)*T.coefficient(x, n) for n in (0..m)] # G. C. Greubel, May 14 2019

From Henry Bottomley, Jan 26 2001: (Start)
a(n) = a(n-1) + (1 + a(n-3))*(n-1)(n-2).
a(n) = Sum_{j=1..floor(n/3)} n!/(j!*(n-3*j)!*(3^j)).
a(n) = A001470(n) - 1. (End)
E.g.f.: exp(x + x^3/3) - exp(x).

A061121 Number of degree-n permutations of order exactly 6.

Original entry on oeis.org

0, 0, 0, 0, 20, 240, 1470, 10640, 83160, 584640, 4496030, 42658440, 371762820, 3594871280, 38650622010, 396457108320, 4330689250160, 53963701424640, 641211774798510, 8205894865096280, 113786291585124060

Offset: 1

Vladeta Jovovic, Apr 14 2001

Cf. A000085, A001470, A001472, A052501, A053496-A053505, A001189, A001471, A001473, A061121-A061128.

nn=21;Range[0,nn]!CoefficientList[Series[(Exp[x^6/6]-1)Exp[x+x^2/2+x^3/3]+(Exp[x^2/2]-1)(Exp[x^3/3]-1)Exp[x],{x,0,nn}],x]//Rest  (* Geoffrey Critzer, Feb 04 2013 *)

E.g.f.: exp(x)-exp(x+1/2*x^2)-exp(x+1/3*x^3)+exp(x+1/2*x^2+1/3*x^3+1/6*x^6).

A061128 Number of degree-n permutations of order exactly 30.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 120960, 2661120, 27941760, 536215680, 6901614720, 90084234240, 1540714855680, 33110649411840, 554845922991360, 8393918663370240, 141081442901118720, 2869353360741853440

Offset: 1

Vladeta Jovovic, Apr 14 2001

Cf. A000085, A001470, A001472, A052501, A053496 - A053505, A001189, A001471, A001473, A061121 - A061128.

E.g.f.: - exp(x) + exp(x + 1/2*x^2) + exp(x + 1/3*x^3) + exp(x + 1/5*x^5) - exp(x + 1/2*x^2 + 1/3*x^3 + 1/6*x^6) - exp(x + 1/2*x^2 + 1/5*x^5 + 1/10*x^10) - exp(x + 1/3*x^3 + 1/5*x^5 + 1/15*x^15) + exp(x + 1/2*x^2 + 1/3*x^3 + 1/5*x^5 + 1/6*x^6 + 1/10*x^10 + 1/15*x^15 + 1/30*x^30).

A051695 Number of degree-n even permutations of order exactly 4.

Original entry on oeis.org

0, 0, 0, 0, 0, 90, 630, 3780, 18900, 94500, 457380, 3825360, 31505760, 312432120, 2704501800, 22984481520, 179863997040, 1531709328240, 13078616488560, 147223414987200, 1657733805020160, 20131890668255520, 226464779237447520, 2542924546378413120, 27053572399079688000

Offset: 1

Vladeta Jovovic

Andrew Howroyd, Table of n, a(n) for n = 1..200

Cf. A001473, A048099, A051685.

m = 26; ((Exp[x + x^2/2 + x^4/4] + Exp[x - x^2/2 - x^4/4] - Exp[x + x^2/2] - Exp[x - x^2/2])/2 + O[x]^m // CoefficientList[#, x]& // Rest) * Range[m - 1]! (* Jean-François Alcover, Feb 09 2020, after Andrew Howroyd *)

seq(n)={my(A=O(x*x^n)); Vec(serlaplace(exp(x + x^2/2 + x^4/4 + A) + exp(x - x^2/2 - x^4/4 + A) - exp(x + x^2/2 + A) - exp(x - x^2/2 + A))/2, -n)} \\ Andrew Howroyd, Feb 01 2020

a(n) = (A001473(n) + A051685(n))/2.

E.g.f.: (exp(x + x^2/2 + x^4/4) + exp(x - x^2/2 - x^4/4) - exp(x + x^2/2) - exp(x - x^2/2))/2. - Andrew Howroyd, Feb 01 2020

Terms a(19) and beyond from Andrew Howroyd, Feb 01 2020

A061132 Number of degree-n even permutations of order dividing 10.

Original entry on oeis.org

1, 1, 1, 1, 4, 40, 190, 610, 1660, 13420, 174700, 1326700, 30818800, 342140800, 2534931400, 16519411000, 143752426000, 4842417082000, 73620307162000, 687934401562000, 17165461784680000, 308493094924720000, 4585953613991980000, 53843602355379220000

Offset: 0

Vladeta Jovovic, Apr 14 2001

			For n=4 the a(4)=4 solutions are (1), (1, 2)(3, 4), (1, 3)(2, 4), (1, 4)(2, 3) (permutations in cyclic notation). - _Luis Manuel Rivera Martínez_, Jun 18 2019

J. Riordan, An Introduction to Combinatorial Analysis, John Wiley & Sons, Inc. New York, 1958 (Chap 4, Problem 22).

Alois P. Heinz, Table of n, a(n) for n = 0..491
Lev Glebsky, Melany Licón, Luis Manuel Rivera, On the number of even roots of permutations, arXiv:1907.00548 [math.CO], 2019.

Cf. A000085, A001470, A001472, A052501, A053496-A053505, A001189, A001471, A001473, A061121-A061128, A000704, A061129-A061132, A048099, A051695, A061133-A061135.

With[{nn = 22}, CoefficientList[Series[1/2 Exp[x + x^2/2 + x^5/5 + x^10/10] + 1/2 Exp[x - x^2/2 + x^5/5 - x^10/10], {x, 0, nn}], x]* Range[0, nn]!] (* Luis Manuel Rivera Martínez, Jun 18 2019 *)

my(x='x+O('x^25)); Vec(serlaplace(1/2*exp(x + 1/2*x^2 + 1/5*x^5 + 1/10*x^10) + 1/2*exp(x - 1/2*x^2 + 1/5*x^5 - 1/10*x^10))) \\ Michel Marcus, Jun 18 2019

E.g.f.: 1/2*exp(x + 1/2*x^2 + 1/5*x^5 + 1/10*x^10) + 1/2*exp(x - 1/2*x^2 + 1/5*x^5 - 1/10*x^10).

A061133 Number of degree-n even permutations of order exactly 6.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 210, 5040, 37800, 201600, 2044350, 25530120, 213993780, 1692490800, 19767998250, 232823791200, 2235629476080, 23171222430720, 294649445112750, 4300403589581400, 55176842335916700, 660577269463243440

Offset: 1

Vladeta Jovovic, Apr 14 2001

Cf. A000085, A001470, A001472, A052501, A053496 - A053505, A001189, A001471, A001473, A061121 - A061128, A000704, A061129 - A061132, A048099, A051695, A061133 - A061135.

E.g.f.: exp(x) - 1/2*exp(x + 1/2*x^2) - 1/2*exp(x - 1/2*x^2) - exp(x + 1/3*x^3) + 1/2*exp(x + 1/2*x^2 + 1/3*x^3 + 1/6*x^6) + 1/2*exp(x - 1/2*x^2 + 1/3*x^3 - 1/6*x^6).

A061135 Number of degree-n even permutations of order exactly 10.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 9072, 90720, 498960, 25945920, 321080760, 2460970512, 14552417880, 115251776640, 4603779180000, 72193873752000, 681167139805152, 16976210865344640, 304992335584165320, 4548189212204243760

Offset: 1

Vladeta Jovovic, Apr 14 2001

Cf. A000085, A001470, A001472, A052501, A053496 - A053505, A001189, A001471, A001473, A061121 - A061128, A000704, A061129 - A061132, A048099, A051695, A061133 - A061135.

E.g.f.: exp(x) - 1/2*exp(x + 1/2*x^2) - 1/2*exp(x - 1/2*x^2) - exp(x + 1/5*x^5) + 1/2*exp(x + 1/2*x^2 + 1/5*x^5 + 1/10*x^10) + 1/2*exp(x - 1/2*x^2 + 1/5*x^5 - 1/10*x^10).

A061129 Number of degree-n even permutations of order dividing 4.

Original entry on oeis.org

1, 1, 1, 1, 4, 16, 136, 736, 4096, 20224, 99856, 475696, 3889216, 31778176, 313696384, 2709911296, 23006784256, 179965340416, 1532217039616, 13081112406784, 147235213351936, 1657791879049216, 20132199908571136, 226466449808367616, 2542933338768769024

Offset: 0

Vladeta Jovovic, Apr 14 2001

Alois P. Heinz, Table of n, a(n) for n = 0..570
Lev Glebsky, Melany Licón, Luis Manuel Rivera, On the number of even roots of permutations, arXiv:1907.00548 [math.CO], 2019.

Cf. A000085, A001470, A001472, A052501, A053496 - A053505, A001189, A001471, A001473, A061121 - A061128, A000704, A061129 - A061132, A048099, A051695, A061133 - A061135.

m:=30; R:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!( Exp(x)*Cosh(x^2/2 + x^4/4) )); [Factorial(n-1)*b[n]: n in [1..m]]; // G. C. Greubel, Jul 02 2019

With[{n=30}, CoefficientList[Series[Exp[x]*Cosh[x^2/2 + x^4/4], {x, 0, n}], x]*Range[0, n]!] (* G. C. Greubel, Jul 02 2019 *)

my(x='x+O('x^30)); Vec(serlaplace( exp(x)*cosh(x^2/2 + x^4/4) )) \\ G. C. Greubel, Jul 02 2019

m = 30; T = taylor(exp(x)*cosh(x^2/2 + x^4/4), x, 0, m); [factorial(n)*T.coefficient(x, n) for n in (0..m)] # G. C. Greubel, Jul 02 2019

E.g.f.: exp(x)*cosh(x^2/2 + x^4/4).

A061136 Number of degree-n odd permutations of order dividing 4.

Original entry on oeis.org

0, 0, 1, 3, 12, 40, 120, 336, 2128, 13392, 118800, 850960, 6004416, 38408448, 260321152, 1744135680, 17067141120, 167200393216, 1838196972288, 18345298804992, 181218866222080, 1673804042803200, 16992835499329536

Offset: 0

Vladeta Jovovic, Apr 14 2001

Lev Glebsky, Melany Licón, Luis Manuel Rivera, On the number of even roots of permutations, arXiv:1907.00548 [math.CO], 2019.

Cf. A000085, A001470, A001472, A052501, A053496 - A053505, A001189, A001471, A001473, A061121 - A061128, A000704, A061129 - A061132, A048099, A051695, A061133 - A061135, A001465, A061136 - A061140.

E.g.f.: 1/2*exp(x + 1/2*x^2 + 1/4*x^4) - 1/2*exp(x - 1/2*x^2 - 1/4*x^4).

cp's OEIS Frontend

A001189 Number of degree-n permutations of order exactly 2.

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A001471 Number of degree-n permutations of order exactly 3.

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A061121 Number of degree-n permutations of order exactly 6.

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A061128 Number of degree-n permutations of order exactly 30.

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A051695 Number of degree-n even permutations of order exactly 4.

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A061132 Number of degree-n even permutations of order dividing 10.

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A061133 Number of degree-n even permutations of order exactly 6.

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A061135 Number of degree-n even permutations of order exactly 10.

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