Number of button presses required to try every combination of a binary combination lock with n number buttons.

A247374

Number of button presses required to try every combination of a binary combination lock with n number buttons.

Terms

    a(0) =3a(1) =8a(2) =17a(3) =38a(4) =77a(5) =165a(6) =331a(7) =698a(8) =1397a(9) =2921a(10) =5843a(11) =12149a(12) =24299a(13) =50315a(14) =100631a(15) =207698a(16) =415397a(17) =855105a(18) =1710211a(19) =3512801a(20) =7025603a(21) =14403923a(22) =28807847a(23) =58967773a(24) =117935547a(25) =241071395a(26) =482142791a(27) =984343883a(28) =1968687767a(29) =4014934295

External references