do  -- find some pernicious numbers - numbers with a prime population count

    local int = require( "int" )      -- RC Pluto integer library, inc. prime utilities

    -- returns the population count (number of set bits) of n
    local function populationCount( n : number ) : number
        local v, count = math.abs( n ), 0
        while v > 0 do
            if v & 1 == 1 then count += 1 end
            v >>= 1
        end
        return count
    end

    -- returns true if p is pernicious, false otherwise
    local function isPernicious ( p : number ) : boolean
        return p > 0 and int.isprime( populationCount( p ) )
    end

    do  -- find the pernicious numbers
        -- show the first 25 pernicious numbers
        local p25, pCount = 2, 0  -- 0 and 1 aren't pernicious, so we start at 2
        while pCount < 25 do
            if isPernicious( p25 ) then
                pCount += 1
                io.write( $" {p25}" )
            end
            p25 += 1
        end
        print()
        -- find the pernicious numbers between 888 888 877 and 888 888 888
        for p = 888888877, 888888888 do
            if isPernicious( p ) then io.write( $" {p}" ) end
        end
        print()
    end
end