

A067837


a(1)=2; to form a(n+1), append P, the largest prime < a(n), if any and Q, the smallest prime > a(n), at the beginning and the end of a(n), respectively.


0




OFFSET

1,1


LINKS



EXAMPLE

To form a(2), note that there is no prime before 2 and that 3 is the prime coming immediately after 2. So a(2) = 23. To form a(3), the prime coming immediately before 23 is 19 and the prime coming immediate after 23 is 29. So a(3) = 192329.


CROSSREFS



KEYWORD

base,nonn


AUTHOR



STATUS

approved



