A324514
Number of aperiodic permutations of {1..n}.
Original entry on oeis.org
1, 0, 3, 16, 115, 660, 5033, 39936, 362718, 3624920, 39916789, 478953648, 6227020787, 87177645996, 1307674338105, 20922779566080, 355687428095983, 6402373519409856, 121645100408831981, 2432902004460734000, 51090942171698415483, 1124000727695858073380
Offset: 1
The a(4) = 16 aperiodic permutations:
(1243) (1324) (1342) (1423)
(2134) (2314) (2413) (2431)
(3124) (3142) (3241) (3421)
(4132) (4213) (4231) (4312)
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Table[Length[Select[Permutations[Range[n]],UnsameQ@@NestList[RotateRight[#/.k_Integer:>If[k==n,1,k+1]]&,#,n-1]&]],{n,6}]
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a(n) = sumdiv(n, d, moebius(n/d)*(n/d)^d*d!); \\ Andrew Howroyd, Aug 19 2019
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
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;
...
Even bisection of column k=2 gives
A346086.
T(2n,n) gives
A110468(n-1) for n >= 1.
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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);
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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 *)
A226388
Number of n-permutations such that all cycle lengths have a common divisor >= 2.
Original entry on oeis.org
0, 0, 1, 2, 9, 24, 265, 720, 11025, 62720, 965601, 3628800, 130478425, 479001600, 19151042625, 191132125184, 4108830350625, 20922789888000, 1448301616386625, 6402373705728000, 466136852576275881, 5675242696048640000, 193688172394325870625, 1124000727777607680000
Offset: 0
a(6) = 265 counting permutations with cycle types: 6; 4-2; 3-3; 2-2-2; of which there are 120 + 90 + 40 + 15 = 265.
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with(combinat):
b:= proc(n, i, g) option remember; `if`(n=0, `if`(g>1, 1, 0),
`if`(i<2, 0, b(n, i-1, g) +`if`(igcd(g, i)<2, 0,
add((i-1)!^j/j! *multinomial(n, i$j, n-i*j)*
b(n-i*j, i-1, igcd(i, g)), j=1..n/i))))
end:
a:= n-> b(n, n, 0):
seq(a(n), n=0..30); # Alois P. Heinz, Jun 06 2013
# second Maple program:
b:= proc(n, g) option remember; `if`(n=0, `if`(g>1, 1, 0), add(
(j-1)!*b(n-j, igcd(g, j))*binomial(n-1, j-1), j=1..n))
end:
a:= n-> b(n, 0):
seq(a(n), n=0..30); # Alois P. Heinz, Jul 04 2021
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f[list_] :=
Total[list]!/Apply[Times, Table[list[[i]], {i, 1, Length[list]}]]/
Apply[Times,
Select[Table[
Count[list, i], {i, 1, Total[list]}], # > 0 &]!]; Table[
Total[Map[f, Select[Partitions[n], Apply[GCD, #] > 1 &]]], {n, 0,
25}]
A079129
Number of degree-n permutations with pairwise coprime cycle lengths.
Original entry on oeis.org
1, 1, 2, 6, 21, 105, 530, 3710, 27265, 229705, 2083354, 24025694, 263359173, 3457302849, 44575118874, 600902614598, 9242750538593, 169974915437041, 2905860232733458, 56257078771371478, 1041600031067604437, 19990420041926339577, 419763750266646291714
Offset: 0
A359951
Number of permutations of [n] such that the GCD of the cycle lengths is a prime.
Original entry on oeis.org
0, 0, 1, 2, 3, 24, 145, 720, 4725, 22400, 602721, 3628800, 67692625, 479001600, 12924021825, 103953833984, 2116670180625, 20922789888000, 959231402754625, 6402373705728000, 257071215652932681, 3242340687872000000, 142597230222616430625, 1124000727777607680000
Offset: 0
a(2) = 1: (12).
a(3) = 2: (123), (132).
a(4) = 3: (12)(34), (13)(24), (14)(23).
a(5) = 24: (12345), (12354), (12435), (12453), (12534), (12543), (13245), (13254), (13425), (13452), (13524), (13542), (14235), (14253), (14325), (14352), (14523), (14532), (15234), (15243), (15324), (15342), (15423), (15432).
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b:= proc(n, g) option remember; `if`(n=0, `if`(isprime(g), 1, 0),
add(b(n-j, igcd(j, g))*(n-1)!/(n-j)!, j=1..n))
end:
a:= n-> b(n, 0):
seq(a(n), n=0..23);
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b[n_, g_] := b[n, g] = If[n == 0, If[PrimeQ[g], 1, 0], Sum[b[n - j, GCD[j, g]]*(n - 1)!/(n - j)!, {j, 1, n}]];
a[n_] := b[n, 0];
Table[a[n], {n, 0, 23}] (* Jean-François Alcover, Dec 13 2023, after Alois P. Heinz *)
A383878
Number of permutations of [n] with distinct cycle lengths whose GCD is 1.
Original entry on oeis.org
0, 1, 0, 3, 8, 50, 264, 2394, 15840, 158976, 1490400, 20124720, 181543680, 3213905760, 36459964800, 602127540000, 9045463311360, 187660890063360, 2596164765465600, 64849189355274240, 1037566851245568000, 24684232291242854400, 498833466644833689600
Offset: 0
a(3) = 3: (1)(23), (13)(2), (12)(3).
a(4) = 8: (1)(234), (1)(243), (134)(2), (143)(2), (124)(3), (142)(3), (123)(4), (132)(4).
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b:= proc(n, i, m) option remember; `if`(i*(i+1)/2 b(n$2, 0):
seq(a(n), n=0..23);
Showing 1-6 of 6 results.
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