Many excellent designs for a new banner were submitted. We will use the best of them in rotation.
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 A179793 A152183
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