1,3
Cf. A067553, A000009.
Sequence in context: A004901 A004912 A164699 * A133303 A152302 A071180
Adjacent sequences: A067567 A067568 A067569 * A067571 A067572 A067573
more,nonn
Naohiro Nomoto (n_nomoto(AT)yabumi.com), Jan 30 2002