OFFSET
1,3
COMMENTS
Also numbers n such that (68*10^n + 31)/9 is prime.
a(12) > 10^5. - Robert Price, Oct 03 2015
LINKS
FORMULA
a(n) = A101146(n-1) + 1 for n>1.
EXAMPLE
For n=0, (68*10^n + 31)/9 = 11 which is a prime, so 0 is a term.
MATHEMATICA
Do[ If[ PrimeQ[(68*10^n + 31)/9], Print[n]], {n, 0, 10000}]
CROSSREFS
KEYWORD
more,nonn
AUTHOR
Robert G. Wilson v, Jan 19 2005
EXTENSIONS
a(1)=0 inserted and a(11) added by Robert Price, Oct 03 2015
STATUS
approved