1,2
Table of n, a(n) for n=1..10.
Cf. A091161 + A091162 + A091163 + A091164 +2 (for 2 & 3) = A006880.
Sequence in context: A332624 A027331 A255489 * A135149 A269007 A246510
Adjacent sequences: A091158 A091159 A091160 * A091162 A091163 A091164
nonn
Robert G. Wilson v, Jan 12 2004
approved