Number of set partitions of {1, 2, ..., n} such that, for any two numbers in the same part, one divides the other.
A333517
Number of set partitions of {1, 2, ..., n} such that, for any two numbers in the same part, one divides the other.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =3a(4) =7a(5) =9a(6) =25a(7) =30a(8) =78a(9) =138a(10) =342a(11) =386a(12) =1307a(13) =1448a(14) =3406a(15) =6818a(16) =18907a(17) =20478a(18) =65901a(19) =70781a(20) =213704a(21) =397874a(22) =885118a(23) =939377a(24) =3624495a(25) =5034048a(26) =11032794a(27) =20966732a(28) =59398560a(29) =62307000
External references
- oeis: A333517