cuban_primes.sf

#!/usr/bin/ruby

# Generate the first `n` cuban primes: primes which are the difference of two consecutive cubes.

# See also:
#   https://oeis.org/A002407
#   https://en.wikipedia.org/wiki/Cuban_prime

func cuban_primes(n) {
    1..Inf -> lazy.map {|k| 3*k*(k+1) + 1 }\
                  .grep{ .is_prime }\
                  .first(n)
}

say cuban_primes(100)

__END__
[7, 19, 37, 61, 127, 271, 331, 397, 547, 631, 919, 1657, 1801, 1951, 2269, 2437, 2791, 3169, 3571, 4219, 4447, 5167, 5419, 6211, 7057, 7351, 8269, 9241, 10267, 11719, 12097, 13267, 13669, 16651, 19441, 19927, 22447, 23497, 24571, 25117, 26227, 27361, 33391, 35317, 42841, 45757, 47251, 49537, 50311, 55897, 59221, 60919, 65269, 70687, 73477, 74419, 75367, 81181, 82171, 87211, 88237, 89269, 92401, 96661, 102121, 103231, 104347, 110017, 112327, 114661, 115837, 126691, 129169, 131671, 135469, 140617, 144541, 145861, 151201, 155269, 163567, 169219, 170647, 176419, 180811, 189757, 200467, 202021, 213067, 231019, 234361, 241117, 246247, 251431, 260191, 263737, 267307, 276337, 279991, 283669]