OFFSET
1,1
COMMENTS
Also numbers n such that (41*10^n+31)/9 is prime.
a(17) > 10^5. - Robert Price, May 25 2015
LINKS
FORMULA
a(n) = A101728(n) + 1.
MATHEMATICA
Do[ If[ PrimeQ[(41*10^n + 31)/9], Print[n]], {n, 0, 10000}]
CROSSREFS
KEYWORD
more,nonn
AUTHOR
Robert G. Wilson v, Jan 17 2005
EXTENSIONS
Addition of a(13)-a(14) from Kamada data by Robert Price, Dec 12 2010
a(15) from Erik Branger, May 01 2013, submitted by Ray Chandler, Aug 16 2013
a(16) from Robert Price, May 25 2015
STATUS
approved