Number of set partitions of {1,...,n} where each block's elements are relatively prime.

A320424

Number of set partitions of {1,...,n} where each block's elements are relatively prime.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =2a(4) =4a(5) =13a(6) =31a(7) =140a(8) =480a(9) =2306a(10) =9179a(11) =58209a(12) =249205a(13) =1802970a(14) =9463155a(15) =63813439a(16) =389176317a(17) =3415876088a(18) =20506436732a(19) =195865505549

External references