Mathematica, 59 bytes
!Select[IntegerPartitions@#,{6,9,20}~SubsetQ~#&]=={}&&#!=0&
ZaMoC
- 25.5k
- 2
- 32
- 87
Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
Visit Stack Exchange!Select[IntegerPartitions@#,{6,9,20}~SubsetQ~#&]=={}&&#!=0&