a(n) = n* - 2^n, where n* (A003418) = least common multiple of the numbers [1,...,n].

Terms

a(0) =-1a(1) =-2a(2) =-2a(3) =-4a(4) =28a(5) =-4a(6) =292a(7) =584a(8) =2008a(9) =1496a(10) =25672a(11) =23624a(12) =352168a(13) =343976a(14) =327592a(15) =655184a(16) =12121168a(17) =11990096a(18) =232268272a(19) =231743984a(20) =230695408a(21) =228598256a(22) =5345840272a(23) =5337451664a(24) =26737589968a(25) =26704035536a(26) =80179215472a(27) =80044997744