1,1
Eric Weisstein's World of Mathematics, Twin Prime Cluster
Cf. A087641.
Sequence in context: A019247 A165142 A186969 * A178255 A154467 A152713
Adjacent sequences: A111947 A111948 A111949 * A111951 A111952 A111953
nonn,more
Eric Weisstein (eric(AT)weisstein.com), Aug 22, 2005