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Number T(n,k) of entries in the k-th cycles of all permutations of [n] when cycles are ordered by decreasing lengths (and increasing smallest elements); triangle T(n,k), n>=1, 1<=k<=n, read by rows.
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%I #31 Dec 07 2021 22:44:34

%S 1,3,1,13,4,1,67,21,7,1,411,131,46,11,1,2911,950,341,101,16,1,23563,

%T 7694,2871,932,197,22,1,213543,70343,26797,9185,2311,351,29,1,2149927,

%U 709015,275353,98317,27568,5119,583,37,1,23759791,7867174,3090544,1141614,343909,73639,10366,916,46,1

%N Number T(n,k) of entries in the k-th cycles of all permutations of [n] when cycles are ordered by decreasing lengths (and increasing smallest elements); triangle T(n,k), n>=1, 1<=k<=n, read by rows.

%H Alois P. Heinz, <a href="/A322384/b322384.txt">Rows n = 1..141, flattened</a>

%H Andrew V. Sills, <a href="https://arxiv.org/abs/1912.05306">Integer Partitions Probability Distributions</a>, arXiv:1912.05306 [math.CO], 2019.

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Permutation">Permutation</a>

%e The 6 permutations of {1,2,3} are:

%e (1) (2) (3)

%e (1,2) (3)

%e (1,3) (2)

%e (2,3) (1)

%e (1,2,3)

%e (1,3,2)

%e so there are 13 elements in the first cycles, 4 in the second cycles and only 1 in the third cycles.

%e Triangle T(n,k) begins:

%e 1;

%e 3, 1;

%e 13, 4, 1;

%e 67, 21, 7, 1;

%e 411, 131, 46, 11, 1;

%e 2911, 950, 341, 101, 16, 1;

%e 23563, 7694, 2871, 932, 197, 22, 1;

%e 213543, 70343, 26797, 9185, 2311, 351, 29, 1;

%e ...

%p b:= proc(n, l) option remember; `if`(n=0, add(l[-i]*

%p x^i, i=1..nops(l)), add(binomial(n-1, j-1)*

%p b(n-j, sort([l[], j]))*(j-1)!, j=1..n))

%p end:

%p T:= n-> (p-> (seq(coeff(p, x, i), i=1..n)))(b(n, [])):

%p seq(T(n), n=1..12);

%t b[n_, l_] := b[n, l] = If[n == 0, Sum[l[[-i]]*x^i, {i, 1, Length[l]}], Sum[Binomial[n-1, j-1]*b[n-j, Sort[Append[l, j]]]*(j-1)!, {j, 1, n}]];

%t T[n_] := CoefficientList[b[n, {}], x] // Rest;

%t Array[T, 12] // Flatten (* _Jean-François Alcover_, Feb 26 2020, after _Alois P. Heinz_ *)

%Y Columns k=1-10 give: A028418, A332851, A332852, A332853, A332854, A332855, A332856, A332857, A332858, A332859.

%Y Row sums give A001563.

%Y T(2n,n) gives A332928.

%Y Cf. A185105, A322383.

%K nonn,tabl

%O 1,2

%A _Alois P. Heinz_, Dec 05 2018