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!)
A240674 Number of partitions p of n that are disjoint from their conjugate. 2

%I #11 Sep 28 2023 16:45:29

%S 0,2,2,2,2,4,4,8,10,10,14,18,18,26,30,36,44,60,64,82,96,114,130,164,

%T 176,222,248,296,338,406,450,550,620,726,816,968,1074,1270,1418,1648,

%U 1836,2150,2382,2758,3080,3534,3942,4538,5034,5778,6416,7312,8136,9258

%N Number of partitions p of n that are disjoint from their conjugate.

%C First column of the array at A240181.

%F a(n) = 2*A114701(n), for n >= 1.

%e a(6) counts these 4 partitions: 6, 33, 222, 111111, of which the respective conjugates are 111111, 222, 33, 6.

%t z = 30; p[n_, k_] := p[n, k] = IntegerPartitions[n][[k]]; c[p_] := c[p] = Table[Count[#, _?(# >= i &)], {i, First[#]}] &[p]; b[n_] := b[n] = Table[Intersection[p[n, k], c[p[n, k]]], {k, 1, PartitionsP[n]}]; Table[Count[Map[Length, b[n]], 0], {n, 1, z}] (* this sequence *)

%t Table[Count[Map[Length, b[n]], 1], {n, 1, z}] (* A240675 *)

%Y Cf. A240675, A114701, A240181.

%K nonn,easy

%O 1,2

%A _Clark Kimberling_, Apr 12 2014

%E Name corrected by _Clark Kimberling_, Sep 28 2023

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 23 03:30 EDT 2024. Contains 371906 sequences. (Running on oeis4.)