1,2
Table of n, a(n) for n=1..15.
Cf. A000040, A000079.
Sequence in context: A189052 A189426 A007076 * A095377 A049539 A037528
Adjacent sequences: A135480 A135481 A135482 * A135484 A135485 A135486
nonn
Ctibor O. Zizka, Feb 07 2008
approved