Sequence of primorial primes
constant @primes = |grep *.is-prime, 2..*;
constant @primorials = [\*] 1, @primes;
my @pp_indexes := |@primorials.pairs.map: {
.key if ( .value + any(1, -1) ).is-prime
};
say ~ @pp_indexes[ 0 ^.. 20 ]; # Skipping bogus first element.
Output:
1 2 3 4 5 6 11 13 24 66 68 75 167 171 172 287 310 352 384 457