sub is-special ( ($previous, $gap) ) {
state @primes = grep *.is-prime, 2..*;
shift @primes while @primes[0] <= $previous + $gap;
return ( @primes[0], @primes[0] - $previous );
}
my @specials = (2, 0), &is-special … *;
my $limit = @specials.first: :k, *.[0] > 1050;
say .fmt('%4d') for @specials.head($limit);