A048823 a(n) = value of n defined as follows: start with n and reach 2 by repeatedly either dividing by d where d <= the square root or by subtracting 1. The division steps are free, but subtracting 1 costs 1 point. The "value" of n is the smallest cost to reach 2.

0, 1, 0, 1, 1, 2, 0, 1, 1, 2, 0, 1, 2, 1, 0, 1, 1, 2, 1, 2, 2, 3, 0, 1, 1, 1, 2, 3, 1, 2, 0, 1, 1, 2, 0, 1, 2, 1, 0, 1, 2, 3, 2, 1, 2, 3, 0, 1, 1, 1, 1, 2, 1, 2, 0, 1, 2, 3, 0, 1, 2, 1, 0, 1, 1, 2, 1, 2, 1, 2, 0, 1, 1, 1, 2, 2, 1, 2, 0, 1, 1, 2, 0, 1, 2, 3, 2, 3, 1, 1, 2, 2, 3, 2, 0, 1, 1, 1, 1, 2, 1, 2, 1

Offset: 2

Author

Christian G. Bower, May 15 1999

Keywords

• nonn

Links

• Sean A. Irvine, Java program (github)

Crossrefs

Cf. A047988. Same formula except you cannot add 1 (only subtract).

Extensions

Missing a(2)=0 inserted by Sean A. Irvine, Jul 09 2021