1,1

Table of n, a(n) for n=1..4.

a(3)=479001599 because 479001599 is prime and equals 479001600-1 = A000142(12) - A000142(1) where 13 and 2 are prime numbers.

Cf. A000142, A055490.

Sequence in context: A127230 A013361 A013363 * A159306 A236302 A179793

Adjacent sequences: A181742 A181743 A181744 * A181746 A181747 A181748

nonn

Juri-Stepan Gerasimov, Nov 08 2010

Corrected a(3) (was missing its last digit), Christian N. K. Anderson, Mar 22 2013

approved