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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.

A323774 Number of multiset partitions, whose parts are constant and all have the same sum, of integer partitions of n.

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%I A323774 #19 Nov 30 2024 16:45:57
%S A323774 1,1,3,3,7,3,12,3,16,8,14,3,39,3,16,15,40,3,50,3,54,17,20,3,135,10,22,
%T A323774 25,73,3,129,3,119,21,26,19,273,3,28,23,217,3,203,3,123,74,32,3,590,
%U A323774 12,106,27,154,3,370,23,343,29,38,3,963,3,40,95,450,25,467,3
%N A323774 Number of multiset partitions, whose parts are constant and all have the same sum, of integer partitions of n.
%C A323774 An unlabeled version of A279789.
%H A323774 Antti Karttunen, <a href="/A323774/b323774.txt">Table of n, a(n) for n = 0..20000</a>
%F A323774 a(0) = 1; a(n) = Sum_{d|n} binomial(tau(d) + n/d - 1, n/d), where tau = A000005.
%e A323774 The a(1) = 1 through a(6) = 12 multiset partitions:
%e A323774   (1)  (2)     (3)        (4)           (5)              (6)
%e A323774        (11)    (111)      (22)          (11111)          (33)
%e A323774        (1)(1)  (1)(1)(1)  (1111)        (1)(1)(1)(1)(1)  (222)
%e A323774                           (2)(2)                         (3)(3)
%e A323774                           (2)(11)                        (111111)
%e A323774                           (11)(11)                       (3)(111)
%e A323774                           (1)(1)(1)(1)                   (2)(2)(2)
%e A323774                                                          (111)(111)
%e A323774                                                          (2)(2)(11)
%e A323774                                                          (2)(11)(11)
%e A323774                                                          (11)(11)(11)
%e A323774                                                          (1)(1)(1)(1)(1)(1)
%t A323774 Table[Length[Join@@Table[Union[Sort/@Tuples[Select[IntegerPartitions[#],SameQ@@#&]&/@ptn]],{ptn,Select[IntegerPartitions[n],SameQ@@#&]}]],{n,30}]
%o A323774 (PARI) a(n) = if (n==0, 1, sumdiv(n, d, binomial(numdiv(d) + n/d - 1, n/d))); \\ _Michel Marcus_, Jan 28 2019
%Y A323774 Cf. A001970, A006171 (constant parts), A007716, A034729, A047966 (uniform partitions),  A047968, A279787, A279789 (twice-partitions version), A305551 (equal part-sums), A306017, A319056, A323766, A323775, A323776.
%K A323774 nonn
%O A323774 0,3
%A A323774 _Gus Wiseman_, Jan 27 2019