cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A320886 Number of multiset partitions of integer partitions of n where all parts have the same product.

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%I A320886 #8 Oct 26 2018 20:36:36
%S A320886 1,1,3,5,10,14,25,33,54,73,107,140,207,264,369,479,652,828,1112,1400,
%T A320886 1848,2326,3009,3762,4856,6020,7648,9478,11942,14705,18427,22576,
%U A320886 28083,34350,42429,51714,63680,77289,94618,114648,139773,168799,205144,247128,299310,359958,434443,521255,627812,751665,902862
%N A320886 Number of multiset partitions of integer partitions of n where all parts have the same product.
%e A320886 The a(1) = 1 through a(6) = 25 multiset partitions:
%e A320886   (1)  (2)     (3)        (4)           (5)              (6)
%e A320886        (11)    (12)       (13)          (14)             (15)
%e A320886        (1)(1)  (111)      (22)          (23)             (24)
%e A320886                (1)(11)    (112)         (113)            (33)
%e A320886                (1)(1)(1)  (1111)        (122)            (114)
%e A320886                           (2)(2)        (1112)           (123)
%e A320886                           (1)(111)      (11111)          (222)
%e A320886                           (11)(11)      (2)(12)          (1113)
%e A320886                           (1)(1)(11)    (1)(1111)        (1122)
%e A320886                           (1)(1)(1)(1)  (11)(111)        (3)(3)
%e A320886                                         (1)(1)(111)      (11112)
%e A320886                                         (1)(11)(11)      (111111)
%e A320886                                         (1)(1)(1)(11)    (12)(12)
%e A320886                                         (1)(1)(1)(1)(1)  (2)(112)
%e A320886                                                          (2)(2)(2)
%e A320886                                                          (1)(11111)
%e A320886                                                          (11)(1111)
%e A320886                                                          (111)(111)
%e A320886                                                          (1)(1)(1111)
%e A320886                                                          (1)(11)(111)
%e A320886                                                          (11)(11)(11)
%e A320886                                                          (1)(1)(1)(111)
%e A320886                                                          (1)(1)(11)(11)
%e A320886                                                          (1)(1)(1)(1)(11)
%e A320886                                                          (1)(1)(1)(1)(1)(1)
%t A320886 sps[{}]:={{}};sps[set:{i_,___}]:=Join@@Function[s,Prepend[#,s]&/@sps[Complement[set,s]]]/@Cases[Subsets[set],{i,___}];
%t A320886 mps[set_]:=Union[Sort[Sort/@(#/.x_Integer:>set[[x]])]&/@sps[Range[Length[set]]]];
%t A320886 Table[Length[Select[Join@@mps/@IntegerPartitions[n],SameQ@@Times@@@#&]],{n,8}]
%o A320886 (PARI)
%o A320886 G(n)={my(M=Map()); for(k=1, n, forpart(p=k, my(t=vecprod(Vec(p)), z); mapput(M, t, if(mapisdefined(M, t, &z), z, 0) + x^k))); M}
%o A320886 a(n)=if(n==0, 1, vecsum(apply(p->EulerT(Vecrev(p/x, n))[n], Mat(G(n))[,2]))) \\ _Andrew Howroyd_, Oct 26 2018
%Y A320886 Cf. A001055, A001970, A045778, A050336, A279375, A294617, A294786, A294787, A294788, A320887, A320888, A320889.
%K A320886 nonn
%O A320886 0,3
%A A320886 _Gus Wiseman_, Oct 23 2018
%E A320886 a(13)-a(50) from _Andrew Howroyd_, Oct 26 2018