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 A387133 #8 Aug 28 2025 17:24:44 %S A387133 1,2,3,2,7,6,15,0,6,14,56,6,101,30,21,0,297,12,490,14,45,112,1255,0, %T A387133 42,202,6,30,4565,42,6842,0,168,594,105,12,21637,980,303,0,44583,90, %U A387133 63261,112,42,2510,124754,0,210,84,891,202,329931,12,392,0,1470,9130 %N A387133 Number of ways to choose a sequence of distinct integer partitions, one of each prime factor of n (with multiplicity). %e A387133 The prime factors of 9 are (3,3), and the a(9) = 6 choices are: %e A387133 ((3),(2,1)) %e A387133 ((3),(1,1,1)) %e A387133 ((2,1),(3)) %e A387133 ((2,1),(1,1,1)) %e A387133 ((1,1,1),(3)) %e A387133 ((1,1,1),(2,1)) %t A387133 Table[Length[Select[Tuples[IntegerPartitions/@Flatten[ConstantArray@@@FactorInteger[n]]],UnsameQ@@#&]],{n,30}] %Y A387133 For prime factors instead of partitions we have A008966, see A355741. %Y A387133 Twice partitions of this type are counted by A296122. %Y A387133 For prime indices instead of factors we have A387110, see A387136. %Y A387133 For strict partitions and prime indices we have A387115. %Y A387133 For constant partitions and prime indices we have A387120. %Y A387133 Positions of zero are A387326, for indices apparently A276079 (complement A276078). %Y A387133 Allowing repeated partitions gives A387327, see A299200, A357977. %Y A387133 A000041 counts integer partitions, strict A000009. %Y A387133 A003963 multiplies together prime indices. %Y A387133 A112798 lists prime indices, row sums A056239 or A066328, lengths A001222. %Y A387133 A120383 lists numbers divisible by all of their prime indices. %Y A387133 A289509 lists numbers with relatively prime prime indices. %Y A387133 Cf. A063834, A261049, A299201, A335433, A335448, A355739, A383706, A387111, A387135. %K A387133 nonn,new %O A387133 1,2 %A A387133 _Gus Wiseman_, Aug 26 2025