login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A325468 Number of integer partitions y of n such that the k-th differences of y are distinct (independently) for all k >= 0. 14

%I #4 May 03 2019 21:26:30

%S 1,1,1,2,2,3,3,5,6,6,9,11,10,15,17,19,24,31,26,40,43,51,52,72,66,89,

%T 88,111,119,150,130,183,193,229,231,279,287,358,365,430,426,538,535,

%U 649,680,742,803,943,982,1136,1115

%N Number of integer partitions y of n such that the k-th differences of y are distinct (independently) for all k >= 0.

%C The differences of a sequence are defined as if the sequence were increasing, so for example the differences of (6,3,1) are (-3,-2).

%C The zeroth differences of a sequence are the sequence itself, while the k-th differences for k > 0 are the differences of the (k-1)-th differences.

%C The Heinz numbers of these partitions are given by A325467.

%H Gus Wiseman, <a href="/A325325/a325325.txt">Sequences counting and ranking integer partitions by the differences of their successive parts.</a>

%e The a(1) = 1 through a(9) = 6 partitions:

%e (1) (2) (3) (4) (5) (6) (7) (8) (9)

%e (21) (31) (32) (42) (43) (53) (54)

%e (41) (51) (52) (62) (63)

%e (61) (71) (72)

%e (421) (431) (81)

%e (521) (621)

%t Table[Length[Select[IntegerPartitions[n],And@@Table[UnsameQ@@Differences[#,k],{k,0,Length[#]}]&]],{n,0,30}]

%Y Cf. A000009, A325324, A325325, A325349, A325353, A325354, A325391, A325393, A325404, A325406, A325467.

%K nonn

%O 0,4

%A _Gus Wiseman_, May 03 2019

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 9 16:40 EDT 2024. Contains 375765 sequences. (Running on oeis4.)