4,1
Cf. A068239-A068305, A000332, A002417, A027441.
Sequence in context: A013802 A084878 A013874 * A115242 A072723 A111413
Adjacent sequences: A068249 A068250 A068251 * A068253 A068254 A068255
nonn
R. H. Hardin (rhhardin(AT)att.net), Feb 24 2002