project-euler/Sidef/133 Repunit nonfactors.sf

#!/usr/bin/ruby

# Daniel "Trizen" Șuteu
# Date: 21 September 2019
# https://github.com/trizen

# https://projecteuler.net/problem=133

# Runtime: 0.335s

# See also:
#   https://oeis.org/A178070

var limit = 100_000

var N = ipow10(limit.ilog2)
var P = Set(primes(7, limit).grep {|p| znorder(10, p) `divides` N }...)

say limit.primes.grep { !P.has(_) }.sum