A059593
Number of degree-n permutations of order exactly 5.
Original entry on oeis.org
0, 0, 0, 0, 0, 24, 144, 504, 1344, 3024, 78624, 809424, 4809024, 20787624, 72696624, 1961583624, 28478346624, 238536558624, 1425925698624, 6764765838624, 189239120970624, 3500701266525624, 37764092547420624, 288099608198025624
Offset: 0
-
m:=30; R:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!( Exp(x + x^5/5) )); [Factorial(n-1)*b[n]-1: n in [1..m]]; // G. C. Greubel, May 14 2019
-
a:= proc(n) option remember;
`if`(n<5, 0, a(n-1)+(1+a(n-5))*(n-1)!/(n-5)!)
end:
seq(a(n), n=1..30); # Alois P. Heinz, Jan 25 2014
-
Table[Sum[n!/(j!*(n-5*j)!*5^j), {j,1,Floor[n/5]}], {n,0,25}] (* G. C. Greubel, May 14 2019 *)
-
{a(n) = sum(j=1,floor(n/5), n!/(j!*(n-5*j)!*5^j))}; \\ G. C. Greubel, May 14 2019
-
m = 30; T = taylor(exp(x + x^5/5) -exp(x), x, 0, m); [factorial(n)*T.coefficient(x, n) for n in (0..m)] # G. C. Greubel, May 14 2019
A061131
Number of degree-n even permutations of order dividing 8.
Original entry on oeis.org
1, 1, 1, 1, 4, 16, 136, 736, 4096, 20224, 326656, 2970496, 33826816, 291237376, 2129910784, 13607197696, 324498374656, 4599593353216, 52741679343616, 495632154179584, 7127212838772736, 94268828128854016, 2098358019107700736, 34030412427789500416
Offset: 0
- 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..502
- Lev Glebsky, Melany Licón, Luis Manuel Rivera, On the number of even roots of permutations, arXiv:1907.00548 [math.CO], 2019.
- T. Koda, M. Sato, Y. Tskegahara, 2-adic properties for the numbers of involutions in the alternating groups, J. Algebra Appl. 14 (2015), no. 4, 1550052 (21 pages).
Cf.
A000085,
A001470,
A001472,
A052501,
A053496-
A053505,
A001189,
A001471,
A001473,
A061121 -
A061128,
A000704,
A061129-
A061132,
A048099,
A051695,
A061133-
A061135.
A061140
Number of degree-n odd permutations of order exactly 8.
Original entry on oeis.org
0, 0, 0, 0, 0, 0, 0, 0, 5040, 45360, 226800, 831600, 9979200, 103783680, 2058376320, 23870246400, 265686220800, 2477893017600, 47031546481920, 656384611034880, 11972743148620800, 165640695384729600, 1969108505560627200
Offset: 0
Cf.
A000085,
A001470,
A001472,
A052501,
A053496 -
A053505,
A001189,
A001471,
A001473,
A061121 -
A061128,
A000704,
A061129 -
A061132,
A048099,
A051695,
A061133 -
A061135.
A061130
Number of degree-n even permutations of order dividing 6.
Original entry on oeis.org
1, 1, 1, 3, 12, 36, 126, 666, 6588, 44892, 237996, 2204676, 26370576, 219140208, 1720782792, 19941776856, 234038005776, 2243409386256, 23225205107088, 295070141019312, 4303459657780416, 55200265166477376, 660776587455193056
Offset: 0
Cf.
A000085,
A001470,
A001472,
A052501,
A053496 -
A053505,
A001189,
A001471,
A001473,
A061121 -
A061128,
A000704,
A061129 -
A061132,
A048099,
A051695,
A061133 -
A061135.
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
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.
-
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
-
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 *)
A061134
Number of degree-n even permutations of order exactly 8.
Original entry on oeis.org
0, 0, 0, 0, 0, 0, 0, 0, 0, 226800, 2494800, 29937600, 259459200, 1816214400, 10897286400, 301491590400, 4419628012800, 51209462304000, 482551041772800, 6979977625420800, 92611036249804800, 2078225819199129600
Offset: 1
Cf.
A000085,
A001470,
A001472,
A052501,
A053496 -
A053505,
A001189,
A001471,
A001473,
A061121 -
A061128,
A000704,
A061129 -
A061132,
A048099,
A051695,
A061133 -
A061135.
A061137
Number of degree-n odd permutations of order dividing 6.
Original entry on oeis.org
0, 0, 1, 3, 6, 30, 270, 1386, 6048, 46656, 387180, 2469060, 17204616, 158065128, 1903506696, 18887563800, 163657221120, 2095170230016, 30792968596368, 346564643468976, 3905503235814240, 58609511127871200, 866032039742528736
Offset: 0
Cf.
A000085,
A001470,
A001472,
A052501,
A053496-
A053505,
A001189,
A001471,
A001473,
A061121-
A061128,
A000704,
A061129-
A061132,
A048099,
A051695,
A061133-
A061135,
A001465,
A061136-
A061140.
-
m:=30; R:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!( Exp(x + x^3/3)*Sinh(x^2/2 + x^6/6) )); [0,0] cat [Factorial(n+1)*b[n]: n in [1..m-2]]; // G. C. Greubel, Jul 02 2019
-
Egf:= exp(x + x^3/3)*sinh(x^2/2 + x^6/6):
S:= series(Egf,x,31):
seq(coeff(S,x,j)*j!,j=0..30); # Robert Israel, Jul 13 2018
-
With[{m=30}, CoefficientList[Series[Exp[x + x^3/3]*Sinh[x^2/2 + x^6/6], {x, 0, m}], x]*Range[0,m]!] (* Vincenzo Librandi, Jul 02 2019 *)
-
my(x='x+O('x^30)); concat([0,0], Vec(serlaplace( exp(x + x^3/3)*sinh(x^2/2 + x^6/6) ))) \\ G. C. Greubel, Jul 02 2019
-
m = 30; T = taylor(exp(x + x^3/3)*sinh(x^2/2 + x^6/6), x, 0, m); [factorial(n)*T.coefficient(x, n) for n in (0..m)] # G. C. Greubel, Jul 02 2019
A336614
Number of n X n (0,1)-matrices A over the reals such that A^2 is the transpose of A.
Original entry on oeis.org
1, 2, 4, 10, 32, 112, 424, 1808, 8320, 40384, 210944, 1170688, 6783616, 41411840, 265451008, 1765520128, 12227526656, 88163295232, 656548065280, 5054719287296, 40261285543936, 330010835894272, 2783003772452864, 24166721466204160, 215318925894909952, 1966855934183800832
Offset: 0
a(3) = A336174(3) + A000079(3) = 2 + 8 = 10.
-
a := n -> add((2^(n - 3*k)*n!)/(3^k*k!*(n - 3*k)!), k=0..n/3):
seq(a(n), n=0..25); # Peter Luschny, Jun 05 2021
-
m(n, t) = matrix(n, n, i, j, (t>>(i*n+j-n-1))%2)
a(n) = sum(t = 0, 2^n^2-1, m(n, t)^2 == m(n, t)~)
for(n = 0, 9, print1(a(n), ", "))
-
from itertools import product
from sympy import Matrix
def A336614(n):
c = 0
for d in product((0,1),repeat=n*n):
M = Matrix(d).reshape(n,n)
if M*M == M.T:
c += 1
return c # Chai Wah Wu, Sep 29 2020
A061138
Number of degree-n odd permutations of order exactly 4.
Original entry on oeis.org
0, 0, 0, 0, 6, 30, 90, 210, 1680, 12096, 114660, 833580, 5928120, 38112360, 259194936, 1739195640, 17043237120, 167089937280, 1837707369840, 18342985021776, 181206905922720, 1673742164139360, 16992525855006240
Offset: 0
Cf.
A000085,
A001470,
A001472,
A052501,
A053496 -
A053505,
A001189,
A001471,
A001473,
A061121 -
A061128,
A000704,
A061129 -
A061132,
A048099,
A051695,
A061133 -
A061135,
A001465,
A061136 -
A061140.
A061139
Number of degree-n odd permutations of order exactly 6.
Original entry on oeis.org
0, 0, 0, 0, 0, 20, 240, 1260, 5600, 45360, 383040, 2451680, 17128320, 157769040, 1902380480, 18882623760, 163633317120, 2095059774080, 30792478993920, 346562329685760, 3905491275514880, 58609449249207360, 866031730098205440
Offset: 0
Cf.
A000085,
A001470,
A001472,
A052501,
A053496 -
A053505,
A001189,
A001471,
A001473,
A061121 -
A061128,
A000704,
A061129 -
A061132,
A048099,
A051695,
A061133 -
A061135,
A001465,
A061136 -
A061140.
Comments