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A276429 Number of partitions of n containing no part i of multiplicity i. 18

%I #25 Jul 15 2020 15:15:10

%S 1,0,2,2,3,5,8,9,16,19,29,36,53,65,92,115,154,195,257,318,419,516,663,

%T 821,1039,1277,1606,1963,2441,2978,3675,4454,5469,6603,8043,9688,

%U 11732,14066,16963,20260,24310,28953,34586,41047,48857,57802,68528,80862,95534,112388,132391

%N Number of partitions of n containing no part i of multiplicity i.

%C The Heinz numbers of these partitions are given by A325130. - _Gus Wiseman_, Apr 02 2019

%H Vaclav Kotesovec, <a href="/A276429/b276429.txt">Table of n, a(n) for n = 0..12782</a> (terms 0..5000 from Alois P. Heinz)

%F a(n) = A276427(n,0).

%F G.f.: g(x) = Product_{i>=1} (1/(1-x^i) - x^{i^2}).

%e a(4) = 3 because we have [1,1,1,1], [1,1,2], and [4]; the partitions [1,3], [2,2] do not qualify.

%e From _Gus Wiseman_, Apr 02 2019: (Start)

%e The a(2) = 2 through a(7) = 9 partitions:

%e (2) (3) (4) (5) (6) (7)

%e (11) (111) (211) (32) (33) (43)

%e (1111) (311) (42) (52)

%e (2111) (222) (511)

%e (11111) (411) (3211)

%e (3111) (4111)

%e (21111) (31111)

%e (111111) (211111)

%e (1111111)

%e (End)

%p g := product(1/(1-x^i)-x^(i^2), i = 1 .. 100): gser := series(g, x = 0, 53): seq(coeff(gser, x, n), n = 0 .. 50);

%p # second Maple program:

%p b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0,

%p add(`if`(i=j, 0, b(n-i*j, i-1)), j=0..n/i)))

%p end:

%p a:= n-> b(n$2):

%p seq(a(n), n=0..60); # _Alois P. Heinz_, Sep 19 2016

%t b[n_, i_] := b[n, i] = Expand[If[n == 0, 1, If[i < 1, 0, Sum[If[i == j, x, 1]*b[n - i*j, i - 1], {j, 0, n/i}]]]]; T[n_] := Function[p, Table[Coefficient[p, x, i], {i, 0, Exponent[p, x]}]][b[n, n]]; Table[T[n][[1]], {n, 0, 60}] (* _Jean-François Alcover_, Nov 28 2016 after _Alois P. Heinz_'s Maple code for A276427 *)

%t Table[Length[Select[IntegerPartitions[n],And@@Table[Count[#,i]!=i,{i,Union[#]}]&]],{n,0,30}] (* _Gus Wiseman_, Apr 02 2019 *)

%Y Cf. A052335, A087153, A114639, A115584, A117144, A276427, A324572, A325130, A325131, A336269.

%K nonn

%O 0,3

%A _Emeric Deutsch_, Sep 19 2016

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Last modified April 18 06:12 EDT 2024. Contains 371769 sequences. (Running on oeis4.)