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!)
A303139 Number of integer partitions of n with at least two but not all parts having a common divisor greater than 1. 10

%I #5 Apr 21 2018 20:57:54

%S 0,0,0,0,1,1,5,6,13,17,33,37,68,82,125,159,237,278,409,491,674,830,

%T 1121,1329,1781,2144,2770,3345,4299,5086,6507,7752,9687,11571,14378,

%U 16985,21039,24876,30379,35924,43734,51320,62238,73068,87747,103021,123347,143955

%N Number of integer partitions of n with at least two but not all parts having a common divisor greater than 1.

%e The a(7) = 5 partitions are (421), (331), (322), (2221), (22111).

%t Table[Select[IntegerPartitions[n],!CoprimeQ@@#&&GCD@@#===1&]//Length,{n,30}]

%Y Cf. A000837, A018783, A051424, A078374, A168532, A289508, A289509, A298748, A300486, A302569, A302696, A302796, A303138, A303140.

%K nonn

%O 1,7

%A _Gus Wiseman_, Apr 19 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 16:23 EDT 2024. Contains 371989 sequences. (Running on oeis4.)