Table of n, a(n) for n=1..32.
109 is in the list because it is the prime A000040(29) and can be written as 74+35=R(47)+R(53)= A004087(15)+A004087(16).
Sequence in context: A064465 A152810 A108719 * A216769 A216743 A216749
Adjacent sequences: A162704 A162705 A162706 * A162708 A162709 A162710
Claudio Meller, Jul 11 2009
Edited, entries checked by R. J. Mathar, Jul 13 2009
A-number in examples corrected - R. J. Mathar, Jul 23 2009