Ascending primes

func primes_with_ascending_digits(base = 10) {
 
    var list = []
    var digits = @(1..^base -> flip)
 
    var end_digits = digits.grep { .is_coprime(base) }
    list << digits.grep { .is_prime && !.is_coprime(base) }...
 
    for k in (0 .. digits.end) {
        digits.combinations(k, {|*a|
            var v = a.digits2num(base)
            end_digits.each {|d|
                var n = (v*base + d)
                next if ((n >= base) && (a[0] >= d))
                list << n if (n.is_prime)
            }
        })
    }
 
    list.sort
}
 
var arr = primes_with_ascending_digits()
 
say "There are #{arr.len} ascending primes.\n"
 
arr.each_slice(10, {|*a|
    say a.map { '%8s' % _ }.join(' ')
})

Output:

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