OFFSET
1,2
COMMENTS
Also numbers n such that (23*10^n+31)/9 is prime.
a(9) > 10^5. - Robert Price, Feb 06 2015
LINKS
FORMULA
a(n) = A101963(n) + 1.
MATHEMATICA
Do[ If[ PrimeQ[(23*10^n + 31)/9], Print[n]], {n, 0, 10000}]
CROSSREFS
KEYWORD
more,nonn
AUTHOR
Robert G. Wilson v, Dec 17 2004
EXTENSIONS
Addition of a(7)-a(8) from Kamada data by Robert Price, Dec 13 2010
STATUS
approved