a(n) is the least value of k such that k*n uses only the digit 2, or a(n) = -1 if no such multiple exists.
A216485
a(n) is the least value of k such that k*n uses only the digit 2, or a(n) = -1 if no such multiple exists.
Terms
- a(0) =2a(1) =1a(2) =74a(3) =-1a(4) =-1a(5) =37a(6) =31746a(7) =-1a(8) =24691358a(9) =-1a(10) =2a(11) =-1a(12) =17094a(13) =15873a(14) =-1a(15) =-1a(17) =12345679a(19) =-1a(20) =10582a(21) =1a(23) =-1a(24) =-1a(25) =8547a(27) =-1a(29) =-1a(31) =-1a(32) =6734a(34) =-1a(35) =-1a(36) =6
External references
- oeis: A216485