A276921
Number A(n,k) of ordered set partitions of [n] with at most k elements per block; square array A(n,k), n>=0, k>=0, read by antidiagonals.
Original entry on oeis.org
1, 1, 0, 1, 1, 0, 1, 1, 2, 0, 1, 1, 3, 6, 0, 1, 1, 3, 12, 24, 0, 1, 1, 3, 13, 66, 120, 0, 1, 1, 3, 13, 74, 450, 720, 0, 1, 1, 3, 13, 75, 530, 3690, 5040, 0, 1, 1, 3, 13, 75, 540, 4550, 35280, 40320, 0, 1, 1, 3, 13, 75, 541, 4670, 45570, 385560, 362880, 0
Offset: 0
Square array A(n,k) begins:
1, 1, 1, 1, 1, 1, 1, 1, ...
0, 1, 1, 1, 1, 1, 1, 1, ...
0, 2, 3, 3, 3, 3, 3, 3, ...
0, 6, 12, 13, 13, 13, 13, 13, ...
0, 24, 66, 74, 75, 75, 75, 75, ...
0, 120, 450, 530, 540, 541, 541, 541, ...
0, 720, 3690, 4550, 4670, 4682, 4683, 4683, ...
0, 5040, 35280, 45570, 47110, 47278, 47292, 47293, ...
Columns k=0..10 give:
A000007,
A000142,
A080599,
A189886,
A276924,
A276925,
A276926,
A276927,
A276928,
A276929,
A276930.
-
A:= proc(n, k) option remember; `if`(n=0, 1, add(
A(n-i, k)*binomial(n, i), i=1..min(n, k)))
end:
seq(seq(A(n, d-n), n=0..d), d=0..12);
-
A[n_, k_] := A[n, k] = If[n==0, 1, Sum[A[n-i, k]*Binomial[n, i], {i, 1, Min[n, k]}]]; Table[A[n, d-n], {d, 0, 12}, {n, 0, d}] // Flatten (* Jean-François Alcover, Feb 03 2017, translated from Maple *)
A229226
The partition function G(n,9).
Original entry on oeis.org
1, 1, 2, 5, 15, 52, 203, 877, 4140, 21147, 115974, 678558, 4213452, 27642837, 190882290, 1382779413, 10478259030, 82844940414, 681863474058, 5830425411936, 51698581146426, 474582397380708, 4503425395487976, 44113612993755306, 445502134752984696
Offset: 0
-
G:= proc(n, k) option remember; local j; if k>n then G(n, n)
elif n=0 then 1 elif k<1 then 0 else G(n-k, k);
for j from k-1 to 1 by -1 do %*(n-j)/j +G(n-j, k) od; % fi
end:
a:= n-> G(n, 9):
seq(a(n), n=0..30);
# second Maple program:
a:= proc(n) option remember; `if`(n=0, 1, add(
a(n-i)*binomial(n-1, i-1), i=1..min(n, 9)))
end:
seq(a(n), n=0..30); # Alois P. Heinz, Sep 22 2016
-
CoefficientList[Exp[Sum[x^j/j!, {j, 1, 9}]] + O[x]^25, x]*Range[0, 24]! (* Jean-François Alcover, May 21 2018 *)
A320765
Number of ordered set partitions of [n] where the maximal block size equals nine.
Original entry on oeis.org
1, 20, 440, 9680, 220220, 5229224, 130069940, 3392692160, 92780281880, 2657929522820, 79670485645608, 2495398380120360, 81558207395885220, 2777643033619233780, 98440545801322467600, 3625667341827832048176, 138601954935720474004950, 5492809832014657114548300
Offset: 9
-
b:= proc(n, k) option remember; `if`(n=0, 1, add(
b(n-i, k)*binomial(n, i), i=1..min(n, k)))
end:
a:= n-> (k-> b(n, k) -b(n, k-1))(9):
seq(a(n), n=9..25);
A320766
Number of ordered set partitions of [n] where the maximal block size equals ten.
Original entry on oeis.org
1, 22, 528, 12584, 308308, 7843836, 208111904, 5767576672, 167004507384, 5050066185736, 159340977018652, 5240336900883084, 179428070995076904, 6388579669849124748, 236257342145458744968, 9064169856705631376280, 360365153529146965326270
Offset: 10
-
b:= proc(n, k) option remember; `if`(n=0, 1, add(
b(n-i, k)*binomial(n, i), i=1..min(n, k)))
end:
a:= n-> (k-> b(n, k) -b(n, k-1))(10):
seq(a(n), n=10..30);
Showing 1-4 of 4 results.
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