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A089259 Expansion of Product_{m>=1} 1/(1-x^m)^A000009(m). 45
1, 1, 2, 4, 7, 12, 22, 36, 61, 101, 166, 267, 433, 686, 1088, 1709, 2671, 4140, 6403, 9824, 15028, 22864, 34657, 52288, 78646, 117784, 175865, 261657, 388145, 573936, 846377, 1244475, 1825170, 2669776, 3895833, 5671127, 8236945, 11936594, 17261557, 24909756 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Number of complete set partitions of the integer partitions of n. This is the Euler transform of A000009. If we change the combstruct command from unlabeled to labeled, then we get A000258. - Thomas Wieder, Aug 01 2008

Number of set multipartitions (multisets of sets) of integer partitions of n. Also a(n) < A270995(n) for n>5. - Gus Wiseman, Apr 10 2016

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..10000

EXAMPLE

From Gus Wiseman, Oct 22 2018: (Start)

The a(6) = 22 set multipartitions of integer partitions of 6:

  (6)  (15)    (123)      (12)(12)      (1)(1)(1)(12)    (1)(1)(1)(1)(1)(1)

       (24)    (1)(14)    (1)(1)(13)    (1)(1)(1)(1)(2)

       (1)(5)  (1)(23)    (1)(2)(12)

       (2)(4)  (2)(13)    (1)(1)(1)(3)

       (3)(3)  (3)(12)    (1)(1)(2)(2)

               (1)(1)(4)

               (1)(2)(3)

               (2)(2)(2)

(End)

MAPLE

with(combstruct): A089259:= [H, {H=Set(T, card>=1), T=PowerSet (Sequence (Z, card>=1), card>=1)}, unlabeled]; 1, seq (count (A089259, size=j), j=1..16); # Thomas Wieder, Aug 01 2008

# second Maple program:

with(numtheory):

b:= proc(n, i)

      if n<0 or n>i*(i+1)/2 then 0

    elif n=0 then 1

    elif i<1 then 0

    else b(n, i):= b(n-i, i-1) +b(n, i-1)

      fi

    end:

a:= proc(n) option remember; `if` (n=0, 1,

       add(add(d* b(d, d), d=divisors(j)) *a(n-j), j=1..n)/n)

    end:

seq(a(n), n=0..100);  # Alois P. Heinz, Nov 11, 2011

MATHEMATICA

max = 40; CoefficientList[Series[Product[1/(1-x^m)^PartitionsQ[m], {m, 1, max}], {x, 0, max}], x] (* Jean-François Alcover, Mar 24 2014 *)

b[n_, i_] := b[n, i] = Which[n<0 || n>i*(i+1)/2, 0, n == 0, 1, i<1, 0, True, b[n-i, i-1] + b[n, i-1]]; a[n_] := a[n] = If[n == 0, 1, Sum[Sum[d* b[d, d], {d, Divisors[j]}]*a[n-j], {j, 1, n}]/n]; Table[a[n], {n, 0, 100} ] (* Jean-François Alcover, Feb 13 2016, after Alois P. Heinz *)

PROG

(PARI) EulerT(v)={Vec(exp(x*Ser(dirmul(v, vector(#v, n, 1/n))))-1, -#v)}

seq(n)={concat([1], EulerT(Vec(eta(x^2 + O(x*x^n))/eta(x + O(x*x^n)) - 1)))} \\ Andrew Howroyd, Oct 26 2018

CROSSREFS

Row sums of A285229.

Cf. A000009, A001970, A049311, A050342, A056156, A068006, A089254, A116540, A218153, A270995, A296119, A318360.

Sequence in context: A018176 A135460 A274174 * A309733 A289107 A221944

Adjacent sequences:  A089256 A089257 A089258 * A089260 A089261 A089262

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Dec 23 2003

STATUS

approved

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Last modified July 4 15:43 EDT 2020. Contains 335448 sequences. (Running on oeis4.)