OFFSET
1,3
COMMENTS
Also numbers n such that (28*10^n+11)/3 is prime.
a(31) > 10^5. - Robert Price, Nov 07 2015
LINKS
FORMULA
a(n) = A101005(n-1) + 1, for n>1.
EXAMPLE
For n=0, (28*10^n+11)/3 = 13, which is prime.
MATHEMATICA
Do[ If[ PrimeQ[(28*10^n + 11)/3], Print[n]], {n, 0, 10000}]
CROSSREFS
KEYWORD
more,nonn
AUTHOR
Robert G. Wilson v, Jan 19 2005
EXTENSIONS
a(26)-a(28) from Kamada data by Robert Price, Dec 14 2010
Inserted a(1)=0 and added a(30) by Robert Price, Nov 07 2015
STATUS
approved