OFFSET
1,2
COMMENTS
Also numbers k such that (7*10^k + 17)/3 is prime.
a(23) > 3*10^5. - Robert Price, Jul 13 2023
LINKS
FORMULA
a(n) = A101956(n) + 1. - Robert Price, Nov 25 2014
MATHEMATICA
Do[ If[ PrimeQ[(7*10^n + 17)/3], Print[n]], {n, 0, 10000}]
CROSSREFS
KEYWORD
more,nonn
AUTHOR
Robert G. Wilson v, Dec 17 2004
EXTENSIONS
Addition of a(19) from Kamada data by Robert Price, Dec 10 2010
a(20)-a(21) from Kamada data by Robert Price, Nov 25 2014
a(22) from Robert Price, Jul 13 2023
STATUS
approved