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.
%I A387134 #7 Aug 31 2025 10:45:26 %S A387134 0,0,1,1,2,3,6,8,12,17,25,34,49,65,89,118,158,206,271,349,453,578,740, %T A387134 935,1186,1486,1865,2322,2890,3572,4415,5423,6659,8134,9927,12062, %U A387134 14643,17706,21387,25746,30957,37109,44433,53054,63273,75276,89444,106044 %N A387134 Number of integer partitions of n whose parts do not have choosable sets of integer partitions. %C A387134 Number of integer partitions of n such that it is not possible to choose a sequence of distinct integer partitions, one of each part. %C A387134 Also the number of integer partitions of n with at least one part k satisfying that the multiplicity of k exceeds the number of integer partitions of k. %e A387134 The a(2) = 1 through a(8) = 12 partitions: %e A387134 (11) (111) (211) (311) (222) (511) (611) %e A387134 (1111) (2111) (411) (2221) (2222) %e A387134 (11111) (2211) (3211) (3311) %e A387134 (3111) (4111) (4211) %e A387134 (21111) (22111) (5111) %e A387134 (111111) (31111) (22211) %e A387134 (211111) (32111) %e A387134 (1111111) (41111) %e A387134 (221111) %e A387134 (311111) %e A387134 (2111111) %e A387134 (11111111) %t A387134 Table[Length[Select[IntegerPartitions[n],Length[Select[Tuples[IntegerPartitions/@#],UnsameQ@@#&]]==0&]],{n,0,15}] %Y A387134 These partitions are ranked by A276079. %Y A387134 For divisors instead of partitions we have A370320, complement A239312. %Y A387134 The complement for prime factors is A370592, ranks A368100. %Y A387134 For prime factors instead of partitions we have A370593, ranks A355529. %Y A387134 For initial intervals instead of partitions we have A387118, complement A238873. %Y A387134 For just choices of strict partitions we have A387137. %Y A387134 The complement is counted by A387328, ranks A276078. %Y A387134 A000005 counts divisors. %Y A387134 A000041 counts integer partitions, strict A000009. %Y A387134 Cf. A335433, A355535, A367867, A367901, A367903, A367905, A367907, A370583, A370594. %K A387134 nonn,new %O A387134 0,5 %A A387134 _Gus Wiseman_, Aug 29 2025