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!)
A325404 Number of reversed integer partitions y of n such that the k-th differences of y are distinct for all k >= 0 and are disjoint from the i-th differences for i != k. 16

%I #8 Jun 07 2019 16:33:38

%S 1,1,1,1,2,3,2,4,4,4,5,7,5,11,12,11,12,20,15,24,22,27,28,37,28,45,43,

%T 48,50,66,58,79,72,84,87,112,106,135,128,158,147,186,180,218,220,265,

%U 246,304,303,354,340,412,418,471,463,538,543,642,600,711,755

%N Number of reversed integer partitions y of n such that the k-th differences of y are distinct for all k >= 0 and are disjoint from the i-th differences for i != k.

%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 A325405.

%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(12) = 5 reversed partitions (A = 10, B = 11, C = 12):

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

%e (13) (14) (15) (16) (17) (18) (19) (29) (39)

%e (23) (25) (26) (27) (28) (38) (57)

%e (34) (35) (45) (37) (47) (1B)

%e (46) (56) (2A)

%e (1A)

%e (146)

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

%Y Cf. A279945, A325325, A325349, A325353, A325354, A325365, A325368, A325391, A325393, A325405, A325406, A325468.

%K nonn

%O 0,5

%A _Gus Wiseman_, May 02 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 April 25 01:35 EDT 2024. Contains 371964 sequences. (Running on oeis4.)