OFFSET
1,3
COMMENTS
Also numbers n such that (41*10^n-23)/9 is prime.
a(22) > 10^5. Robert Price, May 08 2015
LINKS
FORMULA
a(n) = A101726(n-1) + 1.
MATHEMATICA
Do[ If[ PrimeQ[(41*10^n - 23)/9], Print[n]], {n, 0, 10000}]
CROSSREFS
KEYWORD
more,nonn
AUTHOR
Robert G. Wilson v, Jan 17 2005
EXTENSIONS
Addition of a(17)-a(19) from Kamada data by Robert Price, Dec 10 2010
0 added by Arkadiusz Wesolowski, Mar 10 2011
A(21) from Robert Price, May 08 2015
STATUS
approved