Number of rational numbers which can be constructed from the set of integers between 1 and n, through a combination of multiplication and division.

A307105

Number of rational numbers which can be constructed from the set of integers between 1 and n, through a combination of multiplication and division.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =9a(4) =21a(5) =63a(6) =117a(7) =351a(8) =621a(9) =1161a(10) =2043a(11) =6129a(12) =8631a(13) =25893a(14) =45135a(15) =71685a(16) =102285a(17) =306855a(18) =420309a(19) =1260927a(20) =1755513a(21) =2671299a(22) =4571073a(23) =13713219a(24) =17156853a(25) =25778169a(26) =43930755a(27) =59315085a(28) =80765235a(29) =242295705

External references