A023998
Number of block permutations on an n-set which are uniform, i.e., corresponding blocks have same size.
Original entry on oeis.org
1, 1, 3, 16, 131, 1496, 22482, 426833, 9934563, 277006192, 9085194458, 345322038293, 15024619744202, 740552967629021, 40984758230303149, 2527342803112928081, 172490568947825135203, 12952575262915522547136, 1064521056888312620947794, 95305764621957309071404877
Offset: 0
Des FitzGerald (D.FitzGerald(AT)utas.edu.au)
For n=3 there are 25 block permutations, of which 9 of the form ({1} maps to {1,2}; {2,3} maps to {3}), are not uniform. Hence a(3) = 25 - 9 = 16.
Alternatively, for n=3 the 6 permutations of 3 cards produce 16 games, as follows: 123 -> {1,2,3}; 132 -> {1,32}, {1,3,2}; 213 -> {21,3}, {2,1,3}; 231 -> {21,3}, {2,31}, {2,3,1}; 312 -> {31,2}, {32,1}, {3,1,2}; 321 -> {321}, {32,1}, {31,2}, {3,21}, {3,2,1}.
G.f.: A(x) = 1 + x + 3*x^2/2!^2 + 16*x^3/3!^2 + 131*x^4/4!^2 + 1496*x^5/5!^2 + ...
log(A(x)) = x + x^2/2!^2 + x^3/3!^2 + x^4/4!^2 + x^5/5!^2 + ...
- Reinhard Zumkeller, Table of n, a(n) for n = 0..300
- M. Aguiar and R. C. Orellana, The Hopf algebra of uniform block permutations, J. Algebr. Comb. 28 (2008) 115-138
- D. Aldous and P. Diaconis, Longest increasing subsequences: from patience sorting to the Baik-Deift-Johansson theorem, Bull. Amer. Math. Soc. 36 (1999), 413-432.
- H. Cheballah, S. Giraudo, and R. Maurice, Combinatorial Hopf algebra structure on packed square matrices, arXiv preprint arXiv:1306.6605 [math.CO], 2013.
- Fabian Faulstich, Bernd Sturmfels, and Svala Sverrisdóttir, Algebraic Varieties in Quantum Chemistry, arXiv:2308.05258 [math.AG], 2023.
- D. G. FitzGerald and Jonathan Leech, Dual symmetric inverse monoids and representation theory, J. Australian Mathematical Society (Series A), Vol. 64 (1998), pp. 345-367.
- Raúl E. González-Torres, A geometric study of cores of idempotent stochastic matrices, Linear Algebra Appl. 527, 87-127 (2017).
- Rosa Orellana, Franco Saliola, Anne Schilling, and Mike Zabrocki, The lattice of submonoids of the uniform block permutations containing the symmetric group, arXiv:2405.09710 [math.CO], 2024. See p. 3.
- Sebastian Volz, Design and Implementation of Efficient Algorithms for Operations on Partitions of Sets, Bachelor Thesis, Saarland Univ. (Germany, 2023). See p. 45.
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a023998 n = a023998_list !! n
a023998_list = 1 : f 2 [1] a132813_tabl where
f x ys (zs:zss) = y : f (x + 1) (ys ++ [y]) zss where
y = sum $ zipWith (*) ys zs
-- Reinhard Zumkeller, Apr 04 2014
-
b:= proc(n) option remember; `if`(n=0, 1,
add(b(n-i)*binomial(n-1, i-1)/i!, i=1..n))
end:
a:= n-> b(n)*n!:
seq(a(n), n=0..25); # Alois P. Heinz, May 11 2016
-
a[0] = 1; a[n_] := a[n] = Sum[Binomial[n, k] Binomial[n-1, k] a[k], {k, 0, n-1}];
Array[a, 25, 0] (* Jean-François Alcover, Jul 28 2016 *)
nmax = 20; CoefficientList[Series[E^(-1 + BesselI[0, 2*Sqrt[x]]), {x, 0, nmax}], x]*Range[0, nmax]!^2 (* Vaclav Kotesovec, Jun 09 2019 *)
-
a(n)=if(n==0,1,sum(k=0,n-1,binomial(n,k)*binomial(n-1,k)*a(k))) \\ Paul D. Hanna, Aug 15 2007
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{a(n)=n!^2*polcoeff(exp(sum(m=1, n, x^m/m!^2)+x*O(x^n)), n)} /* Paul D. Hanna */
-
N=66; x='x+O('x^N); /* that many terms */
Vec(serlaplace(serlaplace(exp(sum(n=1, N, x^n/n!^2))))) /* show terms */
/* Joerg Arndt, Jul 12 2011 */
-
v=vector(N); v[1]=1;
for (n=1,N-1, v[n+1]=sum(k=0,n-1, binomial(n,k)*binomial(n-1,k)*v[k+1]) );
v /* show terms */
/* Joerg Arndt, Jul 12 2011 */
A321296
Number T(n,k) of colored set partitions of [n] where colors of the elements of subsets are in (weakly) increasing order and exactly k colors are used; triangle T(n,k), n>=0, 0<=k<=n, read by rows.
Original entry on oeis.org
1, 0, 1, 0, 2, 3, 0, 5, 20, 16, 0, 15, 122, 237, 131, 0, 52, 774, 2751, 3524, 1496, 0, 203, 5247, 30470, 68000, 65055, 22482, 0, 877, 38198, 341244, 1181900, 1913465, 1462320, 426833, 0, 4140, 298139, 3949806, 19946654, 48636035, 61692855, 39282229, 9934563
Offset: 0
T(3,2) = 20: 1a2a3b, 1a2b3b, 1a|2a3b, 1a|2b3b, 1b|2a3a, 1b|2a3b, 1a3b|2a, 1b3b|2a, 1a3a|2b, 1a3b|2b, 1a2b|3a, 1b2b|3a, 1a2a|3b, 1a2b|3b, 1a|2a|3b, 1a|2b|3a, 1b|2a|3a, 1a|2b|3b, 1b|2a|3b, 1b|2b|3a.
Triangle T(n,k) begins:
1;
0, 1;
0, 2, 3;
0, 5, 20, 16;
0, 15, 122, 237, 131;
0, 52, 774, 2751, 3524, 1496;
0, 203, 5247, 30470, 68000, 65055, 22482;
0, 877, 38198, 341244, 1181900, 1913465, 1462320, 426833;
...
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A:= proc(n, k) option remember; `if`(n=0, 1, add(A(n-j, k)*
binomial(n-1, j-1)*binomial(k+j-1, j), j=1..n))
end:
T:= (n, k)-> add(A(n, k-i)*(-1)^i*binomial(k, i), i=0..k):
seq(seq(T(n, k), k=0..n), n=0..10);
-
A[n_, k_] := A[n, k] = If[n == 0, 1, Sum[A[n-j, k] Binomial[n-1, j-1]* Binomial[k + j - 1, j], {j, n}]];
T[n_, k_] := Sum[A[n, k - i] (-1)^i Binomial[k, i], {i, 0, k}];
Table[T[n, k], {n, 0, 10}, {k, 0, n}] // Flatten (* Jean-François Alcover, Apr 30 2020, after Alois P. Heinz *)
A325478
Number of colored set partitions of [n] where colors of the elements of subsets are distinct and in increasing order and all colors of an initial interval of the color palette are used.
Original entry on oeis.org
1, 1, 4, 29, 329, 5252, 110955, 2972769, 97922354, 3872594811, 180459028989, 9759149087646, 604841170643957, 42508077480226893, 3357224252026104140, 295651782273190911233, 28834727303442640011901, 3095877335697619795977036, 363977673792652615285223095
Offset: 0
-
b:= proc(n, k) option remember; `if`(n=0, 1, add(b(n-j, k)*
binomial(n-1, j-1)*binomial(k, j), j=1..min(k, n)))
end:
a:= n-> add(add(b(n, k-i)*(-1)^i*binomial(k, i), i=0..k), k=0..n):
seq(a(n), n=0..23);
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b[n_, k_] := b[n, k] = If[n == 0, 1, Sum[b[n - j, k] Binomial[n - 1, j - 1] Binomial[k, j], {j, 1, Min[k, n]}]];
a[n_] := Sum[Sum[b[n, k - i] (-1)^i Binomial[k, i], {i, 0, k}], {k, 0, n}];
a /@ Range[0, 23] (* Jean-François Alcover, Dec 14 2020, after Alois P. Heinz *)
A325481
Number of colored set partitions of [2n] where colors of the elements of subsets are distinct and in increasing order and exactly n colors are used.
Original entry on oeis.org
1, 1, 41, 8020, 4396189, 5226876501, 11581358373398, 43225961160925257, 252807246693691825421, 2194141947654736889023357, 27084992620572948369385642201, 459597167193175440533390098112664, 10424556988338412210154331381461375830
Offset: 0
-
b:= proc(n, k) option remember; `if`(n=0, 1, add(b(n-j, k)*
binomial(n-1, j-1)*binomial(k, j), j=1..min(k, n)))
end:
a:= n-> add(b(2*n, n-i)*(-1)^i*binomial(n, i), i=0..n):
seq(a(n), n=0..14);
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b[n_, k_] := b[n, k] = If[n == 0, 1, Sum[b[n - j, k] Binomial[n - 1, j - 1] Binomial[k, j], {j, 1, Min[k, n]}]];
a[n_] := Sum[b[2n, n - i] (-1)^i Binomial[n, i], {i, 0, n}];
a /@ Range[0, 14] (* Jean-François Alcover, Dec 14 2020, after Alois P. Heinz *)
A325482
Number of colored set partitions of [n] where colors of the elements of subsets are distinct and in increasing order and exactly two colors are used.
Original entry on oeis.org
3, 12, 41, 140, 497, 1848, 7191, 29184, 123107, 538076, 2430353, 11317644, 54229905, 266906856, 1347262319, 6965034368, 36833528195, 199037675052, 1097912385849, 6176578272780, 35409316648433, 206703355298072, 1227820993510151, 7416522514174080
Offset: 2
a(3) = 12: 1a|2a3b, 1b|2a3b, 1a3b|2a, 1a3b|2b, 1a2b|3a, 1a2b|3b, 1a|2a|3b, 1a|2b|3a, 1b|2a|3a, 1a|2b|3b, 1b|2a|3b, 1b|2b|3a.
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b:= proc(n, k) option remember; `if`(n=0, 1, add(b(n-j, k)*
binomial(n-1, j-1)*binomial(k, j), j=1..min(k, n)))
end:
a:= n-> (k-> add(b(n, k-i)*(-1)^i*binomial(k, i), i=0..k))(2):
seq(a(n), n=2..27);
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b[n_, k_] := b[n, k] = If[n == 0, 1, Sum[b[n - j, k] Binomial[n - 1, j - 1] Binomial[k, j], {j, 1, Min[k, n]}]];
a[n_] := With[{k = 2}, Sum[b[n, k - i] (-1)^i Binomial[k, i], {i, 0, k}]];
a /@ Range[2, 27] (* Jean-François Alcover, Dec 14 2020, after Alois P. Heinz *)
A325930
Total number of colors used in all colored set partitions of [n] where colors of the elements of subsets are distinct and in increasing order and the colors span an initial interval of the color palette.
Original entry on oeis.org
0, 1, 7, 73, 1075, 21066, 527122, 16313963, 609352653, 26938878757, 1387465470527, 82169954359252, 5534425340505464, 419977314311140561, 35617039966665620743, 3352008343756176938273, 347915661537105210844323, 39607489635223003610928042
Offset: 0
-
b:= proc(n, k) option remember; `if`(n=0, 1, add(b(n-j, k)*
binomial(n-1, j-1)*binomial(k, j), j=1..min(k, n)))
end:
a:= n-> add(k*add(b(n, k-i)*(-1)^i*binomial(k, i), i=0..k), k=0..n):
seq(a(n), n=0..18);
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b[n_, k_] := b[n, k] = If[n == 0, 1, Sum[b[n - j, k] Binomial[n - 1, j - 1] Binomial[k, j], {j, 1, Min[k, n]}]];
a[n_] := Sum[k Sum[b[n, k-i] (-1)^i Binomial[k, i], {i, 0, k}], {k, 0, n}];
a /@ Range[0, 18] (* Jean-François Alcover, Dec 15 2020, after Alois P. Heinz *)
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