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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.

A363129 Number of integer partitions of n with a unique non-co-mode.

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%I A363129 #5 May 18 2023 08:34:52
%S A363129 0,0,0,0,1,3,3,9,12,18,24,37,43,64,81,99,129,162,201,247,303,364,457,
%T A363129 535,653,765,943,1085,1315,1517,1830,2096,2516,2877,3432,3881,4622,
%U A363129 5235,6189,7003,8203,9261,10859,12199,14216,15985,18544,20777,24064,26897
%N A363129 Number of integer partitions of n with a unique non-co-mode.
%C A363129 We define a non-co-mode in a multiset to be an element that appears more times than at least one of the others. For example, the non-co-modes in {a,a,b,b,b,c,d,d,d} are {a,b,d}.
%e A363129 The a(4) = 1 through a(9) = 18 partitions:
%e A363129   (211)  (221)   (411)    (322)     (332)      (441)
%e A363129          (311)   (3111)   (331)     (422)      (522)
%e A363129          (2111)  (21111)  (511)     (611)      (711)
%e A363129                           (2221)    (3221)     (3222)
%e A363129                           (3211)    (4211)     (3321)
%e A363129                           (4111)    (5111)     (4221)
%e A363129                           (22111)   (22211)    (4311)
%e A363129                           (31111)   (32111)    (5211)
%e A363129                           (211111)  (41111)    (6111)
%e A363129                                     (221111)   (22221)
%e A363129                                     (311111)   (33111)
%e A363129                                     (2111111)  (42111)
%e A363129                                                (51111)
%e A363129                                                (321111)
%e A363129                                                (411111)
%e A363129                                                (2211111)
%e A363129                                                (3111111)
%e A363129                                                (21111111)
%t A363129 ncomsi[ms_]:=Select[Union[ms],Count[ms,#]>Min@@Length/@Split[ms]&];
%t A363129 Table[Length[Select[IntegerPartitions[n],Length[ncomsi[#]]==1&]],{n,0,30}]
%Y A363129 For parts instead of multiplicities we have A002133.
%Y A363129 For middles instead of non-co-modes we have A238478, complement A238479.
%Y A363129 For modes instead of non-co-modes we have A362608, complement A362607.
%Y A363129 For co-modes instead of non-co-modes we have A362610, complement A362609.
%Y A363129 For non-modes instead of non-co-modes we have A363125, complement A363124.
%Y A363129 The complement is counted by A363128.
%Y A363129 A000041 counts integer partitions.
%Y A363129 A008284/A058398 count partitions by length/mean.
%Y A363129 A362611 counts modes in prime factorization, triangle A362614.
%Y A363129 A362613 counts co-modes in prime factorization, triangle A362615.
%Y A363129 A363127 counts non-modes in prime factorization, triangle A363126.
%Y A363129 A363131 counts non-co-modes in prime factorization, triangle A363130.
%Y A363129 Cf. A002865, A053263, A098859, A237984, A275870, A327472, A353836, A353863, A359893, A362612.
%K A363129 nonn
%O A363129 0,6
%A A363129 _Gus Wiseman_, May 18 2023