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- #!/usr/bin/ruby
- # Numbers k such that (23^k - 2^k)/21 is prime.
- # https://oeis.org/A375161
- # Known terms:
- # 5, 11, 197, 4159
- # Next term, if it exists, is greater than 14956.
- for k in (14956 .. 1e6) {
- var v = (23**k - (1 << k))/21
- say "Testing: #{k} (#{v.len} digits)"
- if (v.is_prob_prime) {
- die "Found new term: #{k}\n"
- }
- }
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