Bits of integer

[John Keith]

For the RPL calculators, in BIN mode:

Code:


\<< R\->B \->STR SIZE 3 -
\>>

Accurate up to 10^12, or up to 2^63 on the 49g/50g with Joe Horn's I->B.

Joe Horn's STEP program listed above takes about 4 * as long but has no limit on size.

We can observe that as a sequence, the bit length is "n occurs 2^(n-1) times". If many values for small numbers are needed, the following program returns a list of the values from 1 to 2^n-1 given n on the stack. It is very fast. Requires HP-48G or newer.

Code:


\<< \-> n
  \<< { 1 } 2 n
    START DUP 1 ADD DUP +
    NEXT n \->LIST \GSLIST
  \>>
\>>