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!)
A322912 Number of integer partitions of n whose parts are all powers of the same squarefree number. 3

%I #5 Dec 31 2018 13:18:47

%S 1,1,2,3,5,6,10,11,15,17,23,24,33,34,42,46,56,57,71,72,88,93,109,110,

%T 134,136,158,163,191,192,229,230,266,273,311,315,370,371,419,428,491,

%U 492,565,566,642,654,730,731,836,838,936

%N Number of integer partitions of n whose parts are all powers of the same squarefree number.

%C First differs from A072720 at a(12) = 33, A072720(12) = 34.

%e The a(1) = 1 through a(8) = 15 integer partitions:

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

%e (11) (21) (22) (41) (33) (61) (44)

%e (111) (31) (221) (42) (331) (71)

%e (211) (311) (51) (421) (422)

%e (1111) (2111) (222) (511) (611)

%e (11111) (411) (2221) (2222)

%e (2211) (4111) (3311)

%e (3111) (22111) (4211)

%e (21111) (31111) (5111)

%e (111111) (211111) (22211)

%e (1111111) (41111)

%e (221111)

%e (311111)

%e (2111111)

%e (11111111)

%t radbase[n_]:=n^(1/GCD@@FactorInteger[n][[All,2]]);

%t powsqfQ[n_]:=SameQ@@Last/@FactorInteger[n];

%t Table[Length[Select[IntegerPartitions[n],And[And@@powsqfQ/@#,SameQ@@radbase/@DeleteCases[#,1]]&]],{n,30}]

%Y Cf. A000961, A005117, A018819, A023893, A052410, A072720, A072721, A072774, A302593, A322847, A322900, A322901, A322911.

%K nonn

%O 0,3

%A _Gus Wiseman_, Dec 30 2018

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 04:42 EDT 2024. Contains 371964 sequences. (Running on oeis4.)