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A039900 Number of partitions satisfying 0 < cn(0,5) + cn(1,5) + cn(4,5). 29

%I #34 Jan 14 2022 11:34:48

%S 0,1,1,2,4,6,9,13,19,27,38,52,71,95,127,167,220,285,370,474,607,770,

%T 976,1226,1540,1920,2391,2960,3660,4501,5529,6760,8254,10038,12190,

%U 14750,17825,21470,25825,30975,37101,44322,52879,62937,74811,88733,105110,124261

%N Number of partitions satisfying 0 < cn(0,5) + cn(1,5) + cn(4,5).

%C For a given partition cn(i,n) means the number of its parts equal to i modulo n.

%C Short: o < 0 + 1 + 4 (OMZAAp).

%C Number of partitions of n such that (greatest part) >= (multiplicity of greatest part), for n >= 1. For example, a(6) counts these 9 partitions: 6, 51, 42, 411, 33, 321, 3111, 22111, 21111. See the Mathematica program at A240057 for the sequence as a count of these partitions, along with counts of related partitions. - _Clark Kimberling_, Apr 02 2014

%C The Heinz numbers of these integer partitions are given by A324561. - _Gus Wiseman_, Mar 09 2019

%C From _Gus Wiseman_, Mar 09 2019: (Start)

%C Also the number of integer partitions of n whose minimum part is less than or equal to the number of parts. The Heinz numbers of these integer partitions are given by A324560. For example, the a(1) = 1 through a(7) = 13 integer partitions are:

%C (1) (11) (21) (22) (32) (42) (52)

%C (111) (31) (41) (51) (61)

%C (211) (221) (222) (322)

%C (1111) (311) (321) (331)

%C (2111) (411) (421)

%C (11111) (2211) (511)

%C (3111) (2221)

%C (21111) (3211)

%C (111111) (4111)

%C (22111)

%C (31111)

%C (211111)

%C (1111111)

%C (End)

%H Alois P. Heinz, <a href="/A039900/b039900.txt">Table of n, a(n) for n = 0..10000</a>

%F G.f.: Sum_{k>=0} x^k * (1-x^(k^2)) / Product_{j=1..k} (1-x^j). - _Seiichi Manyama_, Jan 13 2022

%e From _Gus Wiseman_, Mar 09 2019: (Start)

%e The a(1) = 1 through a(7) = 13 integer partitions with at least one part equal to 0, 1, or 4 modulo 5:

%e (1) (11) (21) (4) (5) (6) (43)

%e (111) (31) (41) (42) (52)

%e (211) (221) (51) (61)

%e (1111) (311) (321) (331)

%e (2111) (411) (421)

%e (11111) (2211) (511)

%e (3111) (2221)

%e (21111) (3211)

%e (111111) (4111)

%e (22111)

%e (31111)

%e (211111)

%e (1111111)

%e (End)

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

%p `if`(i<1, 0, b(n, i-1, t)+ `if`(i>n, 0, b(n-i, i,

%p `if`(irem(i, 5) in {2, 3}, t, 1)))))

%p end:

%p a:= n-> b(n$2, 0):

%p seq(a(n), n=0..50); # _Alois P. Heinz_, Apr 03 2014

%t Table[Count[IntegerPartitions[n], p_ /; Min[p] <= Length[p]], {n, 40}] (* _Clark Kimberling_, Feb 13 2014 *)

%t b[n_, i_, t_] := b[n, i, t] = If[n==0, t, If[i<1, 0, b[n, i-1, t] + If[i > n, 0, b[n-i, i, If[MemberQ[{2, 3}, Mod[i, 5]], t, 1]]]]]; a[n_] := b[n, n, 0]; Table[a[n], {n, 0, 50}] (* _Jean-François Alcover_, Nov 16 2015, after _Alois P. Heinz_ *)

%o (PARI) my(N=66, x='x+O('x^N)); concat(0, Vec(sum(k=0, N, x^k*(1-x^k^2)/prod(j=1, k, 1-x^j)))) \\ _Seiichi Manyama_, Jan 13 2022

%Y Cf. A003106, A003114, A039899.

%Y Cf. A003114, A006141, A047993, A064174, A117144.

%Y Cf. A324518, A324520, A324522, A324560, A324561.

%K nonn

%O 0,4

%A _Olivier Gérard_

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Last modified April 24 16:49 EDT 2024. Contains 371962 sequences. (Running on oeis4.)