1,1

These numbers are useful for generating intermediate cluster primes because the best algorithm for generating cluster primes requires starting with a known cluster prime.

Cf. A038134 (cluster primes), A039506 (number of cluster primes < 10^n), A121045.

Sequence in context: A068692 A053302 A068877 this_sequence A107109 A089771 A069661

Adjacent sequences: A121041 A121042 A121043 this_sequence A121045 A121046 A121047

nonn

T. D. Noe (noe(AT)sspectra.com), Jul 21 2006